18621973929 has 32 divisors (see below), whose sum is σ = 28352177280. Its totient is φ = 10777231872.

The previous prime is 18621973913. The next prime is 18621973973. The reversal of 18621973929 is 92937912681.

It is not a de Polignac number, because 18621973929 - 2⁴ = 18621973913 is a prime.

It is a super-3 number, since 3×18621973929³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (18621973129) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9799 + ... + 193235.

It is an arithmetic number, because the mean of its divisors is an integer number (886005540).

Almost surely, 2^18621973929 is an apocalyptic number.

18621973929 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18621973929 is a deficient number, since it is larger than the sum of its proper divisors (9730203351).

18621973929 is a wasteful number, since it uses less digits than its factorization.

18621973929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183609.

The product of its digits is 2939328, while the sum is 57.

It can be divided in two parts, 1862 and 1973929, that added together give a palindrome (1975791).

The spelling of 18621973929 in words is "eighteen billion, six hundred twenty-one million, nine hundred seventy-three thousand, nine hundred twenty-nine".