18219497691816 has 64 divisors (see below), whose sum is σ = 51467507640000. Its totient is φ = 5970230877888.

The previous prime is 18219497691737. The next prime is 18219497691893. The reversal of 18219497691816 is 61819679491281.

18219497691816 is a `hidden beast` number, since 18 + 21 + 9 + 497 + 6 + 91 + 8 + 16 = 666.

It is a super-2 number, since 2×18219497691816² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 714813751 + ... + 714839238.

It is an arithmetic number, because the mean of its divisors is an integer number (804179806875).

Almost surely, 2^{18219497691816} is an apocalyptic number.

It is an amenable number.

18219497691816 is an abundant number, since it is smaller than the sum of its proper divisors (33248009948184).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18219497691816 is a wasteful number, since it uses less digits than its factorization.

18219497691816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1429653063 (or 1429653053 counting only the distinct ones).

The product of its digits is 94058496, while the sum is 72.

The spelling of 18219497691816 in words is "eighteen trillion, two hundred nineteen billion, four hundred ninety-seven million, six hundred ninety-one thousand, eight hundred sixteen".