521404397 has 2 divisors, whose sum is σ = 521404398. Its totient is φ = 521404396.

The previous prime is 521404381. The next prime is 521404447. The reversal of 521404397 is 793404125.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 514881481 + 6522916 = 22691^2 + 2554^2 .

It is a cyclic number.

It is not a de Polignac number, because 521404397 - 2⁴ = 521404381 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521404357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260702198 + 260702199.

It is an arithmetic number, because the mean of its divisors is an integer number (260702199).

Almost surely, 2^521404397 is an apocalyptic number.

It is an amenable number.

521404397 is a deficient number, since it is larger than the sum of its proper divisors (1).

521404397 is an equidigital number, since it uses as much as digits as its factorization.

521404397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 521404397 is about 22834.2811798401. The cubic root of 521404397 is about 804.8684362491.

The spelling of 521404397 in words is "five hundred twenty-one million, four hundred four thousand, three hundred ninety-seven".