1397357851 has 4 divisors (see below), whose sum is σ = 1397451304. Its totient is φ = 1397264400.

The previous prime is 1397357827. The next prime is 1397357911. The reversal of 1397357851 is 1587537931.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a 4-Lehmer number, since φ(1397357851) divides (1397357851-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 1397357851 - 2⁷ = 1397357723 is a prime.

It is a deceptive number, since it divides R_1397357850.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1397357795 and 1397357804.

It is not an unprimeable number, because it can be changed into a prime (1397657851) 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, 18690 + ... + 56071.

It is an arithmetic number, because the mean of its divisors is an integer number (349362826).

It is a Poulet number, since it divides 2^1397357850-1.

Almost surely, 2^1397357851 is an apocalyptic number.

1397357851 is the 18691-st decagonal number.

1397357851 is a deficient number, since it is larger than the sum of its proper divisors (93453).

1397357851 is an equidigital number, since it uses as much as digits as its factorization.

1397357851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93452.

The product of its digits is 793800, while the sum is 49.

The square root of 1397357851 is about 37381.2499924762. The cubic root of 1397357851 is about 1117.9847505982.

It can be divided in two parts, 13973 and 57851, that added together give a square (71824 = 268²).

The spelling of 1397357851 in words is "one billion, three hundred ninety-seven million, three hundred fifty-seven thousand, eight hundred fifty-one".