400580021 has 4 divisors (see below), whose sum is σ = 421663200. Its totient is φ = 379496844.

The previous prime is 400580017. The next prime is 400580023. The reversal of 400580021 is 120085004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 400580021 - 2² = 400580017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 400579975 and 400580002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400580023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10541561 + ... + 10541598.

It is an arithmetic number, because the mean of its divisors is an integer number (105415800).

Almost surely, 2^400580021 is an apocalyptic number.

It is an amenable number.

400580021 is a deficient number, since it is larger than the sum of its proper divisors (21083179).

400580021 is a wasteful number, since it uses less digits than its factorization.

400580021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21083178.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 400580021 is about 20014.4952721771. The cubic root of 400580021 is about 737.1622636670.

The spelling of 400580021 in words is "four hundred million, five hundred eighty thousand, twenty-one".