521979401 has 2 divisors, whose sum is σ = 521979402. Its totient is φ = 521979400.

The previous prime is 521979397. The next prime is 521979421. The reversal of 521979401 is 104979125.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 476767225 + 45212176 = 21835^2 + 6724^2 .

It is a cyclic number.

It is not a de Polignac number, because 521979401 - 2² = 521979397 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (521979421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260989700 + 260989701.

It is an arithmetic number, because the mean of its divisors is an integer number (260989701).

Almost surely, 2^521979401 is an apocalyptic number.

It is an amenable number.

521979401 is a deficient number, since it is larger than the sum of its proper divisors (1).

521979401 is an equidigital number, since it uses as much as digits as its factorization.

521979401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 38.

The square root of 521979401 is about 22846.8685162759. The cubic root of 521979401 is about 805.1641967958.

The spelling of 521979401 in words is "five hundred twenty-one million, nine hundred seventy-nine thousand, four hundred one".