1396565521 has 8 divisors (see below), whose sum is σ = 1592464104. Its totient is φ = 1213305600.

The previous prime is 1396565503. The next prime is 1396565561. The reversal of 1396565521 is 1255656931.

It can be written as a sum of positive squares in 4 ways, for example, as 188238400 + 1208327121 = 13720^2 + 34761^2 .

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

It is not a de Polignac number, because 1396565521 - 2⁷ = 1396565393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1396565561) 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, 3159430 + ... + 3159871.

It is an arithmetic number, because the mean of its divisors is an integer number (199058013).

Almost surely, 2^1396565521 is an apocalyptic number.

It is an amenable number.

1396565521 is a deficient number, since it is larger than the sum of its proper divisors (195898583).

1396565521 is a wasteful number, since it uses less digits than its factorization.

1396565521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6319331.

The product of its digits is 243000, while the sum is 43.

The square root of 1396565521 is about 37370.6505295265. The cubic root of 1396565521 is about 1117.7734040358.

The spelling of 1396565521 in words is "one billion, three hundred ninety-six million, five hundred sixty-five thousand, five hundred twenty-one".