28406391968 has 12 divisors (see below), whose sum is σ = 55925084250. Its totient is φ = 14203195968.

The previous prime is 28406391967. The next prime is 28406391973. The reversal of 28406391968 is 86919360482.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 26604219664 + 1802172304 = 163108^2 + 42452^2 .

It is not an unprimeable number, because it can be changed into a prime (28406391967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 443849843 + ... + 443849906.

Almost surely, 2^28406391968 is an apocalyptic number.

It is an amenable number.

28406391968 is a deficient number, since it is larger than the sum of its proper divisors (27518692282).

28406391968 is an equidigital number, since it uses as much as digits as its factorization.

28406391968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 887699759 (or 887699751 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 56.

The spelling of 28406391968 in words is "twenty-eight billion, four hundred six million, three hundred ninety-one thousand, nine hundred sixty-eight".