21867290640 has 240 divisors, whose sum is σ = 79202305728. Its totient is φ = 5374854144.

The previous prime is 21867290623. The next prime is 21867290677. The reversal of 21867290640 is 4609276812.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8862687 + ... + 8865153.

Almost surely, 2^21867290640 is an apocalyptic number.

21867290640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21867290640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39601152864).

21867290640 is an abundant number, since it is smaller than the sum of its proper divisors (57335015088).

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

21867290640 is a wasteful number, since it uses less digits than its factorization.

21867290640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3446 (or 3437 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 21867290640 in words is "twenty-one billion, eight hundred sixty-seven million, two hundred ninety thousand, six hundred forty".