961977978507 has 48 divisors (see below), whose sum is σ = 1607334715392. Its totient is φ = 507254529600.

The previous prime is 961977978497. The next prime is 961977978527. The reversal of 961977978507 is 705879779169.

It is a happy number.

It is not a de Polignac number, because 961977978507 - 2¹¹ = 961977976459 is a prime.

It is a super-2 number, since 2×961977978507² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (961977978527) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6011382 + ... + 6169332.

It is an arithmetic number, because the mean of its divisors is an integer number (33486139904).

Almost surely, 2^961977978507 is an apocalyptic number.

961977978507 is a deficient number, since it is larger than the sum of its proper divisors (645356736885).

961977978507 is a wasteful number, since it uses less digits than its factorization.

961977978507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161168 (or 161161 counting only the distinct ones).

The product of its (nonzero) digits is 420078960, while the sum is 75.

The spelling of 961977978507 in words is "nine hundred sixty-one billion, nine hundred seventy-seven million, nine hundred seventy-eight thousand, five hundred seven".