156421840 has 40 divisors (see below), whose sum is σ = 364385160. Its totient is φ = 62447616.

The previous prime is 156421823. The next prime is 156421871. The reversal of 156421840 is 48124651.

It can be written as a sum of positive squares in 4 ways, for example, as 5721664 + 150700176 = 2392^2 + 12276^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47776 + ... + 50944.

It is an arithmetic number, because the mean of its divisors is an integer number (9109629).

Almost surely, 2^156421840 is an apocalyptic number.

156421840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

156421840 is an abundant number, since it is smaller than the sum of its proper divisors (207963320).

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

156421840 is a wasteful number, since it uses less digits than its factorization.

156421840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3799 (or 3793 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 156421840 is about 12506.8717111834. The cubic root of 156421840 is about 538.8060497992.

The spelling of 156421840 in words is "one hundred fifty-six million, four hundred twenty-one thousand, eight hundred forty".