1390497857 has 4 divisors (see below), whose sum is σ = 1589140416. Its totient is φ = 1191855300.

The previous prime is 1390497841. The next prime is 1390497869. The reversal of 1390497857 is 7587940931.

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: 7587940931 = 70619 ⋅107449.

It is a cyclic number.

It is not a de Polignac number, because 1390497857 - 2⁴ = 1390497841 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1390497799 and 1390497808.

It is not an unprimeable number, because it can be changed into a prime (1390497817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99321269 + ... + 99321282.

It is an arithmetic number, because the mean of its divisors is an integer number (397285104).

Almost surely, 2^1390497857 is an apocalyptic number.

It is an amenable number.

1390497857 is a deficient number, since it is larger than the sum of its proper divisors (198642559).

1390497857 is an equidigital number, since it uses as much as digits as its factorization.

1390497857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198642558.

The product of its (nonzero) digits is 1905120, while the sum is 53.

The square root of 1390497857 is about 37289.3799492563. The cubic root of 1390497857 is about 1116.1522557157.

The spelling of 1390497857 in words is "one billion, three hundred ninety million, four hundred ninety-seven thousand, eight hundred fifty-seven".