1591881951 has 16 divisors (see below), whose sum is σ = 2321791488. Its totient is φ = 962140800.

The previous prime is 1591881947. The next prime is 1591881953.

1591881951 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1591881951 - 2² = 1591881947 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1591881951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1591881953) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53610 + ... + 77831.

It is an arithmetic number, because the mean of its divisors is an integer number (145111968).

Almost surely, 2^1591881951 is an apocalyptic number.

1591881951 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1591881951 is a deficient number, since it is larger than the sum of its proper divisors (729909537).

1591881951 is a wasteful number, since it uses less digits than its factorization.

1591881951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131822.

The product of its digits is 129600, while the sum is 48.

The square root of 1591881951 is about 39898.3953436727. The cubic root of 1591881951 is about 1167.6256303847.

The spelling of 1591881951 in words is "one billion, five hundred ninety-one million, eight hundred eighty-one thousand, nine hundred fifty-one".