400389978651 has 16 divisors (see below), whose sum is σ = 574930594560. Its totient is φ = 246388839840.

The previous prime is 400389978641. The next prime is 400389978661. The reversal of 400389978651 is 156879983004.

It is an interprime number because it is at equal distance from previous prime (400389978641) and next prime (400389978661).

It is not a de Polignac number, because 400389978651 - 2⁶ = 400389978587 is a prime.

It is not an unprimeable number, because it can be changed into a prime (400389978641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3074580 + ... + 3202158.

It is an arithmetic number, because the mean of its divisors is an integer number (35933162160).

Almost surely, 2^400389978651 is an apocalyptic number.

400389978651 is a deficient number, since it is larger than the sum of its proper divisors (174540615909).

400389978651 is a wasteful number, since it uses less digits than its factorization.

400389978651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208066.

The product of its (nonzero) digits is 13063680, while the sum is 60.

The spelling of 400389978651 in words is "four hundred billion, three hundred eighty-nine million, nine hundred seventy-eight thousand, six hundred fifty-one".