21221402052 has 24 divisors (see below), whose sum is σ = 50724328032. Its totient is φ = 6901268800.

The previous prime is 21221402051. The next prime is 21221402053. The reversal of 21221402052 is 25020412212.

It is an interprime number because it is at equal distance from previous prime (21221402051) and next prime (21221402053).

It is a super-3 number, since 3×21221402052³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21221402051) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 21565974 + ... + 21566957.

It is an arithmetic number, because the mean of its divisors is an integer number (2113513668).

Almost surely, 2^21221402052 is an apocalyptic number.

It is an amenable number.

21221402052 is an abundant number, since it is smaller than the sum of its proper divisors (29502925980).

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

21221402052 is a wasteful number, since it uses less digits than its factorization.

21221402052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43132979 (or 43132977 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

Adding to 21221402052 its reverse (25020412212), we get a palindrome (46241814264).

The spelling of 21221402052 in words is "twenty-one billion, two hundred twenty-one million, four hundred two thousand, fifty-two".