400220431978 has 16 divisors (see below), whose sum is σ = 631941145920. Its totient is φ = 189573854976.

The previous prime is 400220431973. The next prime is 400220431999. The reversal of 400220431978 is 879134022004.

It is a self number, because there is not a number n which added to its sum of digits gives 400220431978.

It is not an unprimeable number, because it can be changed into a prime (400220431973) 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, 2186826 + ... + 2362762.

It is an arithmetic number, because the mean of its divisors is an integer number (39496321620).

Almost surely, 2^400220431978 is an apocalyptic number.

400220431978 is a deficient number, since it is larger than the sum of its proper divisors (231720713942).

400220431978 is a wasteful number, since it uses less digits than its factorization.

400220431978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235821.

The product of its (nonzero) digits is 96768, while the sum is 40.

The spelling of 400220431978 in words is "four hundred billion, two hundred twenty million, four hundred thirty-one thousand, nine hundred seventy-eight".