405672521 has 2 divisors, whose sum is σ = 405672522. Its totient is φ = 405672520.

The previous prime is 405672517. The next prime is 405672571. The reversal of 405672521 is 125276504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 302934025 + 102738496 = 17405^2 + 10136^2 .

It is a cyclic number.

It is not a de Polignac number, because 405672521 - 2² = 405672517 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (405672571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202836260 + 202836261.

It is an arithmetic number, because the mean of its divisors is an integer number (202836261).

Almost surely, 2^405672521 is an apocalyptic number.

It is an amenable number.

405672521 is a deficient number, since it is larger than the sum of its proper divisors (1).

405672521 is an equidigital number, since it uses as much as digits as its factorization.

405672521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16800, while the sum is 32.

The square root of 405672521 is about 20141.3137853517. The cubic root of 405672521 is about 740.2729216096.

The spelling of 405672521 in words is "four hundred five million, six hundred seventy-two thousand, five hundred twenty-one".