637989961 has 32 divisors (see below), whose sum is σ = 782991360. Its totient is φ = 507741696.

The previous prime is 637989959. The next prime is 637990019. The reversal of 637989961 is 169989736.

It is not a de Polignac number, because 637989961 - 2¹ = 637989959 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 637989896 and 637989905.

It is not an unprimeable number, because it can be changed into a prime (637989941) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 1807161 + ... + 1807513.

It is an arithmetic number, because the mean of its divisors is an integer number (24468480).

Almost surely, 2^637989961 is an apocalyptic number.

It is an amenable number.

637989961 is a deficient number, since it is larger than the sum of its proper divisors (145001399).

637989961 is a wasteful number, since it uses less digits than its factorization.

637989961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 613.

The product of its digits is 4408992, while the sum is 58.

The square root of 637989961 is about 25258.4631559404. The cubic root of 637989961 is about 860.8707428347.

The spelling of 637989961 in words is "six hundred thirty-seven million, nine hundred eighty-nine thousand, nine hundred sixty-one".