21868553380 has 24 divisors (see below), whose sum is σ = 45962897400. Its totient is φ = 8740005120.

The previous prime is 21868553351. The next prime is 21868553383. The reversal of 21868553380 is 8335586812.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12495215524 + 9373337856 = 111782^2 + 96816^2 .

It is not an unprimeable number, because it can be changed into a prime (21868553383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 439305 + ... + 486544.

It is an arithmetic number, because the mean of its divisors is an integer number (1915120725).

Almost surely, 2^21868553380 is an apocalyptic number.

21868553380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21868553380 is an abundant number, since it is smaller than the sum of its proper divisors (24094344020).

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

21868553380 is a wasteful number, since it uses less digits than its factorization.

21868553380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 927039 (or 927037 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 49.

The spelling of 21868553380 in words is "twenty-one billion, eight hundred sixty-eight million, five hundred fifty-three thousand, three hundred eighty".