991364636 has 6 divisors (see below), whose sum is σ = 1734888120. Its totient is φ = 495682316.

The previous prime is 991364609. The next prime is 991364651. The reversal of 991364636 is 636463199.

It is a super-2 number, since 2×991364636² = 1965607683022824992, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123920576 + ... + 123920583.

It is an arithmetic number, because the mean of its divisors is an integer number (289148020).

Almost surely, 2^991364636 is an apocalyptic number.

It is an amenable number.

991364636 is a deficient number, since it is larger than the sum of its proper divisors (743523484).

991364636 is a wasteful number, since it uses less digits than its factorization.

991364636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247841163 (or 247841161 counting only the distinct ones).

The product of its digits is 629856, while the sum is 47.

The square root of 991364636 is about 31485.9434668869. The cubic root of 991364636 is about 997.1132198527.

The spelling of 991364636 in words is "nine hundred ninety-one million, three hundred sixty-four thousand, six hundred thirty-six".