57121391 has 6 divisors (see below), whose sum is σ = 60286392. Its totient is φ = 54114660.

The previous prime is 57121367. The next prime is 57121409. The reversal of 57121391 is 19312175.

It is not a de Polignac number, because 57121391 - 2¹⁰ = 57120367 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57121301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 78755 + ... + 79476.

It is an arithmetic number, because the mean of its divisors is an integer number (10047732).

Almost surely, 2^57121391 is an apocalyptic number.

57121391 is a deficient number, since it is larger than the sum of its proper divisors (3165001).

57121391 is a wasteful number, since it uses less digits than its factorization.

57121391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158269 (or 158250 counting only the distinct ones).

The product of its digits is 1890, while the sum is 29.

The square root of 57121391 is about 7557.8694749248. The cubic root of 57121391 is about 385.1231202338.

The spelling of 57121391 in words is "fifty-seven million, one hundred twenty-one thousand, three hundred ninety-one".