61540452864 has 240 divisors, whose sum is σ = 200235309120. Its totient is φ = 18648115200.

The previous prime is 61540452851. The next prime is 61540452881. The reversal of 61540452864 is 46825404516.

It is a happy number.

61540452864 is a `hidden beast` number, since 6 + 1 + 540 + 45 + 2 + 8 + 64 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1654309 + ... + 1691099.

It is an arithmetic number, because the mean of its divisors is an integer number (834313788).

Almost surely, 2^61540452864 is an apocalyptic number.

61540452864 is a gapful number since it is divisible by the number (64) 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 61540452864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100117654560).

61540452864 is an abundant number, since it is smaller than the sum of its proper divisors (138694856256).

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

61540452864 is a wasteful number, since it uses less digits than its factorization.

61540452864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36840 (or 36807 counting only the distinct ones).

The product of its (nonzero) digits is 921600, while the sum is 45.

The spelling of 61540452864 in words is "sixty-one billion, five hundred forty million, four hundred fifty-two thousand, eight hundred sixty-four".