21838567820 has 12 divisors (see below), whose sum is σ = 45860992464. Its totient is φ = 8735427120.

The previous prime is 21838567819. The next prime is 21838567841. The reversal of 21838567820 is 2876583812.

It is a happy number.

It is a hoax number, since the sum of its digits (50) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 545964176 + ... + 545964215.

It is an arithmetic number, because the mean of its divisors is an integer number (3821749372).

Almost surely, 2^21838567820 is an apocalyptic number.

21838567820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21838567820 is an abundant number, since it is smaller than the sum of its proper divisors (24022424644).

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

21838567820 is a wasteful number, since it uses less digits than its factorization.

21838567820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1091928400 (or 1091928398 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 50.

The spelling of 21838567820 in words is "twenty-one billion, eight hundred thirty-eight million, five hundred sixty-seven thousand, eight hundred twenty".