1539356921 has 2 divisors, whose sum is σ = 1539356922. Its totient is φ = 1539356920.

The previous prime is 1539356887. The next prime is 1539356933. The reversal of 1539356921 is 1296539351.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1129699321 + 409657600 = 33611^2 + 20240^2 .

It is a cyclic number.

It is not a de Polignac number, because 1539356921 - 2²² = 1535162617 is a prime.

It is not a weakly prime, because it can be changed into another prime (1539356971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 769678460 + 769678461.

It is an arithmetic number, because the mean of its divisors is an integer number (769678461).

Almost surely, 2^1539356921 is an apocalyptic number.

It is an amenable number.

1539356921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1539356921 is an equidigital number, since it uses as much as digits as its factorization.

1539356921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 218700, while the sum is 44.

The square root of 1539356921 is about 39234.6392999859. The cubic root of 1539356921 is about 1154.6395859521.

The spelling of 1539356921 in words is "one billion, five hundred thirty-nine million, three hundred fifty-six thousand, nine hundred twenty-one".