61540974720 has 384 divisors, whose sum is σ = 223213536000. Its totient is φ = 16199958528.

The previous prime is 61540974709. The next prime is 61540974721. The reversal of 61540974720 is 2747904516.

61540974720 is a `hidden beast` number, since 61 + 540 + 9 + 7 + 47 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (61540974721) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12283576 + ... + 12288584.

It is an arithmetic number, because the mean of its divisors is an integer number (581285250).

Almost surely, 2^61540974720 is an apocalyptic number.

61540974720 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 61540974720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111606768000).

61540974720 is an abundant number, since it is smaller than the sum of its proper divisors (161672561280).

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

61540974720 is an equidigital number, since it uses as much as digits as its factorization.

61540974720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5122 (or 5098 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 45.

The spelling of 61540974720 in words is "sixty-one billion, five hundred forty million, nine hundred seventy-four thousand, seven hundred twenty".