21146872819 has 16 divisors (see below), whose sum is σ = 22866520320. Its totient is φ = 19496313760.

The previous prime is 21146872801. The next prime is 21146872843. The reversal of 21146872819 is 91827864112.

It is a cyclic number.

It is not a de Polignac number, because 21146872819 - 2⁵ = 21146872787 is a prime.

It is a super-2 number, since 2×21146872819² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21146842819) 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, 364524 + ... + 418534.

It is an arithmetic number, because the mean of its divisors is an integer number (1429157520).

Almost surely, 2^21146872819 is an apocalyptic number.

21146872819 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21146872819 is a deficient number, since it is larger than the sum of its proper divisors (1719647501).

21146872819 is a wasteful number, since it uses less digits than its factorization.

21146872819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54650.

The product of its digits is 387072, while the sum is 49.

The spelling of 21146872819 in words is "twenty-one billion, one hundred forty-six million, eight hundred seventy-two thousand, eight hundred nineteen".