61621365641 has 16 divisors (see below), whose sum is σ = 67744705536. Its totient is φ = 55586400000.

The previous prime is 61621365613. The next prime is 61621365671. The reversal of 61621365641 is 14656312616.

It is a cyclic number.

It is not a de Polignac number, because 61621365641 - 2²² = 61617171337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61621365601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 805931 + ... + 879071.

It is an arithmetic number, because the mean of its divisors is an integer number (4234044096).

Almost surely, 2^61621365641 is an apocalyptic number.

It is an amenable number.

61621365641 is a deficient number, since it is larger than the sum of its proper divisors (6123339895).

61621365641 is a wasteful number, since it uses less digits than its factorization.

61621365641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73744.

The product of its digits is 155520, while the sum is 41.

The spelling of 61621365641 in words is "sixty-one billion, six hundred twenty-one million, three hundred sixty-five thousand, six hundred forty-one".