961551639 has 96 divisors (see below), whose sum is σ = 1603929600. Its totient is φ = 551992320.

The previous prime is 961551587. The next prime is 961551667. The reversal of 961551639 is 936155169.

961551639 is a `hidden beast` number, since 9 + 6 + 1 + 5 + 5 + 1 + 639 = 666.

It is not a de Polignac number, because 961551639 - 2⁷ = 961551511 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 961551594 and 961551603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (961551139) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10803907 + ... + 10803995.

It is an arithmetic number, because the mean of its divisors is an integer number (16707600).

Almost surely, 2^961551639 is an apocalyptic number.

961551639 is a deficient number, since it is larger than the sum of its proper divisors (642377961).

961551639 is a wasteful number, since it uses less digits than its factorization.

961551639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245 (or 242 counting only the distinct ones).

The product of its digits is 218700, while the sum is 45.

The square root of 961551639 is about 31008.8961267569. The cubic root of 961551639 is about 987.0160257065.

The spelling of 961551639 in words is "nine hundred sixty-one million, five hundred fifty-one thousand, six hundred thirty-nine".