1357872421 has 4 divisors (see below), whose sum is σ = 1359370432. Its totient is φ = 1356374412.

The previous prime is 1357872389. The next prime is 1357872427. The reversal of 1357872421 is 1242787531.

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.

It is a cyclic number.

It is not a de Polignac number, because 1357872421 - 2⁵ = 1357872389 is a prime.

It is a super-3 number, since 3×1357872421³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1357872427) 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, 747645 + ... + 749458.

It is an arithmetic number, because the mean of its divisors is an integer number (339842608).

Almost surely, 2^1357872421 is an apocalyptic number.

It is an amenable number.

1357872421 is a deficient number, since it is larger than the sum of its proper divisors (1498011).

1357872421 is an equidigital number, since it uses as much as digits as its factorization.

1357872421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1498010.

The product of its digits is 94080, while the sum is 40.

The square root of 1357872421 is about 36849.3204957703. The cubic root of 1357872421 is about 1107.3536017458.

The spelling of 1357872421 in words is "one billion, three hundred fifty-seven million, eight hundred seventy-two thousand, four hundred twenty-one".