21122452764 has 144 divisors (see below), whose sum is σ = 63853404160. Its totient is φ = 5760149760.

The previous prime is 21122452711. The next prime is 21122452801. The reversal of 21122452764 is 46725422112.

21122452764 is a `hidden beast` number, since 2 + 1 + 122 + 4 + 527 + 6 + 4 = 666.

It is a super-2 number, since 2×21122452764² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

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, 551757 + ... + 588795.

Almost surely, 2^21122452764 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21122452764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31926702080).

21122452764 is an abundant number, since it is smaller than the sum of its proper divisors (42730951396).

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

21122452764 is a wasteful number, since it uses less digits than its factorization.

21122452764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37160 (or 37155 counting only the distinct ones).

The product of its digits is 53760, while the sum is 36.

Adding to 21122452764 its reverse (46725422112), we get a palindrome (67847874876).

It can be divided in two parts, 21122452 and 764, that added together give a square (21123216 = 4596²).

The spelling of 21122452764 in words is "twenty-one billion, one hundred twenty-two million, four hundred fifty-two thousand, seven hundred sixty-four".