406391020 has 24 divisors (see below), whose sum is σ = 975338784. Its totient is φ = 139334016.

The previous prime is 406391009. The next prime is 406391021. The reversal of 406391020 is 20193604.

It is a super-2 number, since 2×406391020² = 330307322273280800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (406391021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1451257 + ... + 1451536.

It is an arithmetic number, because the mean of its divisors is an integer number (40639116).

Almost surely, 2^406391020 is an apocalyptic number.

It is an amenable number.

406391020 is an abundant number, since it is smaller than the sum of its proper divisors (568947764).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

406391020 is a wasteful number, since it uses less digits than its factorization.

406391020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2902809 (or 2902807 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 406391020 is about 20159.1423428677. The cubic root of 406391020 is about 740.7097038434.

The spelling of 406391020 in words is "four hundred six million, three hundred ninety-one thousand, twenty".