906378257521 has 81 divisors (see below), whose sum is σ = 1076648433931. Its totient is φ = 762392831200.

The previous prime is 906378257507. The next prime is 906378257527. The reversal of 906378257521 is 125752873609.

The square root of 906378257521 is 952039.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 653405472225 + 252972785296 = 808335^2 + 502964^2 .

It is not a de Polignac number, because 906378257521 - 2¹⁵ = 906378224753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (906378257527) 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 in 80 ways as a sum of consecutive naturals, for example, 12765890916 + ... + 12765890986.

Almost surely, 2^906378257521 is an apocalyptic number.

906378257521 is the 952039-th square number.

906378257521 is the 476020-th centered octagonal number.

It is an amenable number.

906378257521 is a deficient number, since it is larger than the sum of its proper divisors (170270176410).

906378257521 is an equidigital number, since it uses as much as digits as its factorization.

906378257521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316 (or 158 counting only the distinct ones).

The product of its (nonzero) digits is 6350400, while the sum is 55.

The spelling of 906378257521 in words is "nine hundred six billion, three hundred seventy-eight million, two hundred fifty-seven thousand, five hundred twenty-one".