61889948640 has 960 divisors, whose sum is σ = 248961081600. Its totient is φ = 14371209216.

The previous prime is 61889948639. The next prime is 61889948641. The reversal of 61889948640 is 4684998816.

61889948640 is a `hidden beast` number, since 61 + 8 + 8 + 99 + 486 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (61889948639) and next prime (61889948641).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61889948641) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 258953641 + ... + 258953879.

It is an arithmetic number, because the mean of its divisors is an integer number (259334460).

Almost surely, 2^61889948640 is an apocalyptic number.

61889948640 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 61889948640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124480540800).

61889948640 is an abundant number, since it is smaller than the sum of its proper divisors (187071132960).

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

61889948640 is a wasteful number, since it uses less digits than its factorization.

61889948640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 23887872, while the sum is 63.

The spelling of 61889948640 in words is "sixty-one billion, eight hundred eighty-nine million, nine hundred forty-eight thousand, six hundred forty".