77641921 has 12 divisors (see below), whose sum is σ = 90469488. Its totient is φ = 66438792.

The previous prime is 77641913. The next prime is 77641931. The reversal of 77641921 is 12914677.

It is not a de Polignac number, because 77641921 - 2³ = 77641913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77641931) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43570 + ... + 45316.

It is an arithmetic number, because the mean of its divisors is an integer number (7539124).

Almost surely, 2^77641921 is an apocalyptic number.

It is an amenable number.

77641921 is a deficient number, since it is larger than the sum of its proper divisors (12827567).

77641921 is a wasteful number, since it uses less digits than its factorization.

77641921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2668 (or 2661 counting only the distinct ones).

The product of its digits is 21168, while the sum is 37.

The square root of 77641921 is about 8811.4653151448. The cubic root of 77641921 is about 426.6110405861.

The spelling of 77641921 in words is "seventy-seven million, six hundred forty-one thousand, nine hundred twenty-one".