661623237 has 24 divisors (see below), whose sum is σ = 1048346208. Its totient is φ = 398757600.

The previous prime is 661623217. The next prime is 661623247. The reversal of 661623237 is 732326166.

661623237 is a `hidden beast` number, since 6 + 6 + 1 + 623 + 23 + 7 = 666.

It is not a de Polignac number, because 661623237 - 2²⁴ = 644846021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661623217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 543 + ... + 36380.

It is an arithmetic number, because the mean of its divisors is an integer number (43681092).

Almost surely, 2^661623237 is an apocalyptic number.

It is an amenable number.

661623237 is a deficient number, since it is larger than the sum of its proper divisors (386722971).

661623237 is a wasteful number, since it uses less digits than its factorization.

661623237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37121 (or 37118 counting only the distinct ones).

The product of its digits is 54432, while the sum is 36.

The square root of 661623237 is about 25722.0379635829. The cubic root of 661623237 is about 871.3719653163.

The spelling of 661623237 in words is "six hundred sixty-one million, six hundred twenty-three thousand, two hundred thirty-seven".