405220809 has 48 divisors (see below), whose sum is σ = 674672640. Its totient is φ = 211118400.

The previous prime is 405220769. The next prime is 405220813. The reversal of 405220809 is 908022504.

It is not a de Polignac number, because 405220809 - 2⁸ = 405220553 is a prime.

It is a super-2 number, since 2×405220809² = 328407808093228962, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405220709) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2238699 + ... + 2238879.

It is an arithmetic number, because the mean of its divisors is an integer number (14055680).

Almost surely, 2^405220809 is an apocalyptic number.

It is an amenable number.

405220809 is a deficient number, since it is larger than the sum of its proper divisors (269451831).

405220809 is a wasteful number, since it uses less digits than its factorization.

405220809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422 (or 241 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 405220809 is about 20130.0970936556. The cubic root of 405220809 is about 739.9980575795.

The spelling of 405220809 in words is "four hundred five million, two hundred twenty thousand, eight hundred nine".