991739601 has 12 divisors (see below), whose sum is σ = 1471229812. Its totient is φ = 643290336.

The previous prime is 991739531. The next prime is 991739603. The reversal of 991739601 is 106937199.

991739601 is a `hidden beast` number, since 9 + 9 + 1 + 7 + 39 + 601 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 915002001 + 76737600 = 30249^2 + 8760^2 .

It is not a de Polignac number, because 991739601 - 2⁷ = 991739473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991739603) 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, 1488766 + ... + 1489431.

Almost surely, 2^991739601 is an apocalyptic number.

It is an amenable number.

991739601 is a deficient number, since it is larger than the sum of its proper divisors (479490211).

991739601 is a wasteful number, since it uses less digits than its factorization.

991739601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2978240 (or 2978237 counting only the distinct ones).

The product of its (nonzero) digits is 91854, while the sum is 45.

The square root of 991739601 is about 31491.8973864707. The cubic root of 991739601 is about 997.2389171044.

The spelling of 991739601 in words is "nine hundred ninety-one million, seven hundred thirty-nine thousand, six hundred one".