661216424 has 16 divisors (see below), whose sum is σ = 1352488320. Its totient is φ = 300552880.

The previous prime is 661216331. The next prime is 661216433. The reversal of 661216424 is 424612166.

661216424 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3756824 + ... + 3756999.

It is an arithmetic number, because the mean of its divisors is an integer number (84530520).

Almost surely, 2^661216424 is an apocalyptic number.

It is an amenable number.

661216424 is an abundant number, since it is smaller than the sum of its proper divisors (691271896).

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

661216424 is a wasteful number, since it uses less digits than its factorization.

661216424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7513840 (or 7513836 counting only the distinct ones).

The product of its digits is 13824, while the sum is 32.

The square root of 661216424 is about 25714.1288788868. The cubic root of 661216424 is about 871.1933348901.

The spelling of 661216424 in words is "six hundred sixty-one million, two hundred sixteen thousand, four hundred twenty-four".