991769506 has 24 divisors (see below), whose sum is σ = 1863657180. Its totient is φ = 392347872.

The previous prime is 991769503. The next prime is 991769507. The reversal of 991769506 is 605967199.

It can be written as a sum of positive squares in 2 ways, for example, as 954253881 + 37515625 = 30891^2 + 6125^2 .

It is not an unprimeable number, because it can be changed into a prime (991769503) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 387961 + ... + 390508.

Almost surely, 2^991769506 is an apocalyptic number.

991769506 is a deficient number, since it is larger than the sum of its proper divisors (871887674).

991769506 is a wasteful number, since it uses less digits than its factorization.

991769506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778498 (or 778491 counting only the distinct ones).

The product of its (nonzero) digits is 918540, while the sum is 52.

The square root of 991769506 is about 31492.3721875631. The cubic root of 991769506 is about 997.2489406126.

The spelling of 991769506 in words is "nine hundred ninety-one million, seven hundred sixty-nine thousand, five hundred six".