405021601 has 12 divisors (see below), whose sum is σ = 422585748. Its totient is φ = 388044384.

The previous prime is 405021581. The next prime is 405021623. The reversal of 405021601 is 106120504.

It can be written as a sum of positive squares in 2 ways, for example, as 295840000 + 109181601 = 17200^2 + 10449^2 .

It is not a de Polignac number, because 405021601 - 2⁷ = 405021473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (405021641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 95931 + ... + 100063.

It is an arithmetic number, because the mean of its divisors is an integer number (35215479).

Almost surely, 2^405021601 is an apocalyptic number.

It is an amenable number.

405021601 is a deficient number, since it is larger than the sum of its proper divisors (17564147).

405021601 is an equidigital number, since it uses as much as digits as its factorization.

405021601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4272 (or 4229 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 405021601 is about 20125.1484715020. The cubic root of 405021601 is about 739.8767758053.

It can be divided in two parts, 4050 and 21601, that added together give a triangular number (25651 = T₂₂₆).

The spelling of 405021601 in words is "four hundred five million, twenty-one thousand, six hundred one".