21237767616 has 168 divisors, whose sum is σ = 64427398704. Its totient is φ = 6150144000.

The previous prime is 21237767609. The next prime is 21237767647. The reversal of 21237767616 is 61676773212.

It is a super-2 number, since 2×21237767616² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 532366 + ... + 570866.

Almost surely, 2^21237767616 is an apocalyptic number.

21237767616 is a gapful number since it is divisible by the number (26) 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 21237767616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32213699352).

21237767616 is an abundant number, since it is smaller than the sum of its proper divisors (43189631088).

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

21237767616 is a wasteful number, since it uses less digits than its factorization.

21237767616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38559 (or 38536 counting only the distinct ones).

The product of its digits is 889056, while the sum is 48.

The spelling of 21237767616 in words is "twenty-one billion, two hundred thirty-seven million, seven hundred sixty-seven thousand, six hundred sixteen".