961566779 has 4 divisors (see below), whose sum is σ = 965802984. Its totient is φ = 957330576.

The previous prime is 961566761. The next prime is 961566787. The reversal of 961566779 is 977665169.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 961566779 - 2⁸ = 961566523 is a prime.

It is a super-2 number, since 2×961566779² = 1849221340952869682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (961566709) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2117762 + ... + 2118215.

It is an arithmetic number, because the mean of its divisors is an integer number (241450746).

Almost surely, 2^961566779 is an apocalyptic number.

961566779 is a deficient number, since it is larger than the sum of its proper divisors (4236205).

961566779 is a wasteful number, since it uses less digits than its factorization.

961566779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4236204.

The product of its digits is 4286520, while the sum is 56.

The square root of 961566779 is about 31009.1402492878. The cubic root of 961566779 is about 987.0212059949.

The spelling of 961566779 in words is "nine hundred sixty-one million, five hundred sixty-six thousand, seven hundred seventy-nine".