516661553991 has 8 divisors (see below), whose sum is σ = 751507714944. Its totient is φ = 313128214520.

The previous prime is 516661553957. The next prime is 516661554037. The reversal of 516661553991 is 199355166615.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 516661553991 - 2²⁹ = 516124683079 is a prime.

It is a super-2 number, since 2×516661553991² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (516661503991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7828205331 + ... + 7828205396.

It is an arithmetic number, because the mean of its divisors is an integer number (93938464368).

Almost surely, 2^516661553991 is an apocalyptic number.

516661553991 is a deficient number, since it is larger than the sum of its proper divisors (234846160953).

516661553991 is a wasteful number, since it uses less digits than its factorization.

516661553991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15656410741.

The product of its digits is 6561000, while the sum is 57.

The spelling of 516661553991 in words is "five hundred sixteen billion, six hundred sixty-one million, five hundred fifty-three thousand, nine hundred ninety-one".