400763521 has 2 divisors, whose sum is σ = 400763522. Its totient is φ = 400763520.

The previous prime is 400763507. The next prime is 400763527. The reversal of 400763521 is 125367004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 219484225 + 181279296 = 14815^2 + 13464^2 .

It is a cyclic number.

It is not a de Polignac number, because 400763521 - 2⁷ = 400763393 is a prime.

It is a super-2 number, since 2×400763521² = 321222799528634882, which contains 22 as substring.

It is equal to p_21374830 and since 400763521 and 21374830 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 400763521.

It is not a weakly prime, because it can be changed into another prime (400763527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200381760 + 200381761.

It is an arithmetic number, because the mean of its divisors is an integer number (200381761).

Almost surely, 2^400763521 is an apocalyptic number.

It is an amenable number.

400763521 is a deficient number, since it is larger than the sum of its proper divisors (1).

400763521 is an equidigital number, since it uses as much as digits as its factorization.

400763521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 400763521 is about 20019.0789248656. The cubic root of 400763521 is about 737.2748076603.

It can be divided in two parts, 4007 and 63521, that added together give a triangular number (67528 = T₃₆₇).

The spelling of 400763521 in words is "four hundred million, seven hundred sixty-three thousand, five hundred twenty-one".