1391070521 has 16 divisors (see below), whose sum is σ = 1504863360. Its totient is φ = 1281920640.

The previous prime is 1391070451. The next prime is 1391070523. The reversal of 1391070521 is 1250701931.

It is not a de Polignac number, because 1391070521 - 2²⁶ = 1323961657 is a prime.

It is a super-2 number, since 2×1391070521² = 3870154388790422882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is not an unprimeable number, because it can be changed into a prime (1391070523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 345506 + ... + 349508.

It is an arithmetic number, because the mean of its divisors is an integer number (94053960).

Almost surely, 2^1391070521 is an apocalyptic number.

It is an amenable number.

1391070521 is a deficient number, since it is larger than the sum of its proper divisors (113792839).

1391070521 is a wasteful number, since it uses less digits than its factorization.

1391070521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4576.

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

The square root of 1391070521 is about 37297.0578062131. The cubic root of 1391070521 is about 1116.3054604318.

The spelling of 1391070521 in words is "one billion, three hundred ninety-one million, seventy thousand, five hundred twenty-one".