1057491321 has 4 divisors (see below), whose sum is σ = 1409988432. Its totient is φ = 704994212.

The previous prime is 1057491317. The next prime is 1057491329. The reversal of 1057491321 is 1231947501.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1231947501 = 3 ⋅410649167.

It is a cyclic number.

It is not a de Polignac number, because 1057491321 - 2² = 1057491317 is a prime.

It is a super-2 number, since 2×1057491321² = 2236575787980650082, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1057491329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176248551 + ... + 176248556.

It is an arithmetic number, because the mean of its divisors is an integer number (352497108).

Almost surely, 2^1057491321 is an apocalyptic number.

It is an amenable number.

1057491321 is a deficient number, since it is larger than the sum of its proper divisors (352497111).

1057491321 is an equidigital number, since it uses as much as digits as its factorization.

1057491321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352497110.

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 1057491321 is about 32519.0916386052. The cubic root of 1057491321 is about 1018.8078218476.

The spelling of 1057491321 in words is "one billion, fifty-seven million, four hundred ninety-one thousand, three hundred twenty-one".