61958665440 has 216 divisors, whose sum is σ = 245954053800. Its totient is φ = 14161964544.

The previous prime is 61958665421. The next prime is 61958665441. The reversal of 61958665440 is 4456685916.

61958665440 is a `hidden beast` number, since 6 + 1 + 9 + 586 + 6 + 54 + 4 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61958665441) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 368490 + ... + 509609.

It is an arithmetic number, because the mean of its divisors is an integer number (1138676175).

Almost surely, 2^61958665440 is an apocalyptic number.

61958665440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61958665440 is an abundant number, since it is smaller than the sum of its proper divisors (183995388360).

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

61958665440 is a wasteful number, since it uses less digits than its factorization.

61958665440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 878134 (or 878116 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 54.

The spelling of 61958665440 in words is "sixty-one billion, nine hundred fifty-eight million, six hundred sixty-five thousand, four hundred forty".