1397536521 has 8 divisors (see below), whose sum is σ = 1882592544. Its totient is φ = 922085760.

The previous prime is 1397536519. The next prime is 1397536529. The reversal of 1397536521 is 1256357931.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1397536521 - 2¹ = 1397536519 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1397536529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2400975 + ... + 2401556.

It is an arithmetic number, because the mean of its divisors is an integer number (235324068).

Almost surely, 2^1397536521 is an apocalyptic number.

It is an amenable number.

1397536521 is a deficient number, since it is larger than the sum of its proper divisors (485056023).

1397536521 is an equidigital number, since it uses as much as digits as its factorization.

1397536521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4802631.

The product of its digits is 170100, while the sum is 42.

The square root of 1397536521 is about 37383.6397505647. The cubic root of 1397536521 is about 1118.0323980977.

The spelling of 1397536521 in words is "one billion, three hundred ninety-seven million, five hundred thirty-six thousand, five hundred twenty-one".