21937591368 has 384 divisors, whose sum is σ = 80591616000. Its totient is φ = 5397321600.

The previous prime is 21937591339. The next prime is 21937591373. The reversal of 21937591368 is 86319573912.

21937591368 is a `hidden beast` number, since 2 + 19 + 3 + 7 + 591 + 36 + 8 = 666.

It is a super-2 number, since 2×21937591368² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3472933 + ... + 3479243.

It is an arithmetic number, because the mean of its divisors is an integer number (209874000).

Almost surely, 2^21937591368 is an apocalyptic number.

21937591368 is a gapful number since it is divisible by the number (28) 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 21937591368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40295808000).

21937591368 is an abundant number, since it is smaller than the sum of its proper divisors (58654024632).

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

21937591368 is a wasteful number, since it uses less digits than its factorization.

21937591368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6374 (or 6353 counting only the distinct ones).

The product of its digits is 2449440, while the sum is 54.

The spelling of 21937591368 in words is "twenty-one billion, nine hundred thirty-seven million, five hundred ninety-one thousand, three hundred sixty-eight".