21386437611552 has 576 divisors, whose sum is σ = 70747486598880. Its totient is φ = 6068733345792.

The previous prime is 21386437611529. The next prime is 21386437611611. The reversal of 21386437611552 is 25511673468312.

It is a happy number.

21386437611552 is a `hidden beast` number, since 2 + 1 + 3 + 8 + 6 + 4 + 3 + 76 + 11 + 552 = 666.

It can be written as a sum of positive squares in 16 ways, for example, as 15478212903696 + 5908224707856 = 3934236^2 + 2430684^2 .

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 2958419074 + ... + 2958426302.

Almost surely, 2^{21386437611552} 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 21386437611552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35373743299440).

21386437611552 is an abundant number, since it is smaller than the sum of its proper divisors (49361048987328).

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

21386437611552 is a wasteful number, since it uses less digits than its factorization.

21386437611552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8205 (or 8194 counting only the distinct ones).

The product of its digits is 7257600, while the sum is 54.

The spelling of 21386437611552 in words is "twenty-one trillion, three hundred eighty-six billion, four hundred thirty-seven million, six hundred eleven thousand, five hundred fifty-two".