61775398621440 has 2880 divisors, whose sum is σ = 273668715048960. Its totient is φ = 13002646487040.

The previous prime is 61775398621429. The next prime is 61775398621457. The reversal of 61775398621440 is 4412689357716.

61775398621440 is a `hidden beast` number, since 6 + 1 + 7 + 7 + 539 + 86 + 2 + 14 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2880).

It is a super-2 number, since 2×61775398621440² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 47629450872 + ... + 47629452168.

It is an arithmetic number, because the mean of its divisors is an integer number (95023859392).

It is a 1-persistent number, because it is pandigital, but 2⋅61775398621440 = 123550797242880 is not.

Almost surely, 2^{61775398621440} is an apocalyptic number.

61775398621440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61775398621440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136834357524480).

61775398621440 is an abundant number, since it is smaller than the sum of its proper divisors (211893316427520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61775398621440 is a wasteful number, since it uses less digits than its factorization.

61775398621440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1470 (or 1447 counting only the distinct ones).

The product of its (nonzero) digits is 60963840, while the sum is 63.

The spelling of 61775398621440 in words is "sixty-one trillion, seven hundred seventy-five billion, three hundred ninety-eight million, six hundred twenty-one thousand, four hundred forty".