513831921991 has 16 divisors (see below), whose sum is σ = 536785121728. Its totient is φ = 491368550400.

The previous prime is 513831921979. The next prime is 513831922003. The reversal of 513831921991 is 199129138315.

It is an interprime number because it is at equal distance from previous prime (513831921979) and next prime (513831922003).

It is a cyclic number.

It is not a de Polignac number, because 513831921991 - 2²¹ = 513829824839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (513831925991) 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, 2853511 + ... + 3028231.

It is an arithmetic number, because the mean of its divisors is an integer number (33549070108).

Almost surely, 2^513831921991 is an apocalyptic number.

513831921991 is a deficient number, since it is larger than the sum of its proper divisors (22953199737).

513831921991 is a wasteful number, since it uses less digits than its factorization.

513831921991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176122.

The product of its digits is 524880, while the sum is 52.

The spelling of 513831921991 in words is "five hundred thirteen billion, eight hundred thirty-one million, nine hundred twenty-one thousand, nine hundred ninety-one".