57721491 has 16 divisors (see below), whose sum is σ = 86572320. Its totient is φ = 38479536.

The previous prime is 57721483. The next prime is 57721519. The reversal of 57721491 is 19412775.

It is a happy number.

It is not a de Polignac number, because 57721491 - 2³ = 57721483 is a prime.

It is not an unprimeable number, because it can be changed into a prime (57721291) 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, 11010 + ... + 15383.

It is an arithmetic number, because the mean of its divisors is an integer number (5410770).

Almost surely, 2^57721491 is an apocalyptic number.

57721491 is a deficient number, since it is larger than the sum of its proper divisors (28850829).

57721491 is an frugal number, since it uses more digits than its factorization.

57721491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26414 (or 26396 counting only the distinct ones).

The product of its digits is 17640, while the sum is 36.

The square root of 57721491 is about 7597.4660907437. The cubic root of 57721491 is about 386.4670869397.

The spelling of 57721491 in words is "fifty-seven million, seven hundred twenty-one thousand, four hundred ninety-one".