501431921 has 2 divisors, whose sum is σ = 501431922. Its totient is φ = 501431920.

The previous prime is 501431863. The next prime is 501431969. The reversal of 501431921 is 129134105.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 329821921 + 171610000 = 18161^2 + 13100^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-501431921 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (501431971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 250715960 + 250715961.

It is an arithmetic number, because the mean of its divisors is an integer number (250715961).

Almost surely, 2^501431921 is an apocalyptic number.

It is an amenable number.

501431921 is a deficient number, since it is larger than the sum of its proper divisors (1).

501431921 is an equidigital number, since it uses as much as digits as its factorization.

501431921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 501431921 is about 22392.6756105652. The cubic root of 501431921 is about 794.4574814769.

The spelling of 501431921 in words is "five hundred one million, four hundred thirty-one thousand, nine hundred twenty-one".