3991257311 has 4 divisors (see below), whose sum is σ = 4058905800. Its totient is φ = 3923608824.

The previous prime is 3991257307. The next prime is 3991257371. The reversal of 3991257311 is 1137521993.

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 3991257311 - 2² = 3991257307 is a prime.

It is a super-2 number, since 2×3991257311² = 31860269845221901442, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991257301) 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, 33824156 + ... + 33824273.

It is an arithmetic number, because the mean of its divisors is an integer number (1014726450).

Almost surely, 2^3991257311 is an apocalyptic number.

3991257311 is a deficient number, since it is larger than the sum of its proper divisors (67648489).

3991257311 is an equidigital number, since it uses as much as digits as its factorization.

3991257311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67648488.

The product of its digits is 51030, while the sum is 41.

The square root of 3991257311 is about 63176.3983699609. The cubic root of 3991257311 is about 1586.2436955480.

The spelling of 3991257311 in words is "three billion, nine hundred ninety-one million, two hundred fifty-seven thousand, three hundred eleven".