21662342640 has 480 divisors, whose sum is σ = 77151686976. Its totient is φ = 5441126400.

The previous prime is 21662342623. The next prime is 21662342693. The reversal of 21662342640 is 4624326612.

21662342640 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 2 + 3 + 4 + 2 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21662342595 and 21662342604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 214478590 + ... + 214478690.

Almost surely, 2^21662342640 is an apocalyptic number.

21662342640 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 21662342640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38575843488).

21662342640 is an abundant number, since it is smaller than the sum of its proper divisors (55489344336).

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

21662342640 is a wasteful number, since it uses less digits than its factorization.

21662342640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337 (or 328 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The spelling of 21662342640 in words is "twenty-one billion, six hundred sixty-two million, three hundred forty-two thousand, six hundred forty".