18196397820 has 48 divisors (see below), whose sum is σ = 56611017120. Its totient is φ = 4852372608.

The previous prime is 18196397801. The next prime is 18196397873. The reversal of 18196397820 is 2879369181.

It is a super-2 number, since 2×18196397820² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

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, 16847977 + ... + 16849056.

It is an arithmetic number, because the mean of its divisors is an integer number (1179396190).

Almost surely, 2^18196397820 is an apocalyptic number.

18196397820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18196397820 is an abundant number, since it is smaller than the sum of its proper divisors (38414619300).

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

18196397820 is a wasteful number, since it uses less digits than its factorization.

18196397820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33697051 (or 33697043 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The spelling of 18196397820 in words is "eighteen billion, one hundred ninety-six million, three hundred ninety-seven thousand, eight hundred twenty".