21651624532 has 6 divisors (see below), whose sum is σ = 37890342938. Its totient is φ = 10825812264.

The previous prime is 21651624529. The next prime is 21651624539. The reversal of 21651624532 is 23542615612.

It can be written as a sum of positive squares in only one way, i.e., 10965440656 + 10686183876 = 104716^2 + 103374^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21651624491 and 21651624500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21651624539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2706453063 + ... + 2706453070.

Almost surely, 2^21651624532 is an apocalyptic number.

It is an amenable number.

21651624532 is a deficient number, since it is larger than the sum of its proper divisors (16238718406).

21651624532 is a wasteful number, since it uses less digits than its factorization.

21651624532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5412906137 (or 5412906135 counting only the distinct ones).

The product of its digits is 86400, while the sum is 37.

The spelling of 21651624532 in words is "twenty-one billion, six hundred fifty-one million, six hundred twenty-four thousand, five hundred thirty-two".