21356140633455 has 32 divisors (see below), whose sum is σ = 34482091843584. Its totient is φ = 11286077798016.

The previous prime is 21356140633427. The next prime is 21356140633463. The reversal of 21356140633455 is 55433604165312.

It is not a de Polignac number, because 21356140633455 - 2⁷ = 21356140633327 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5514697 + ... + 8551266.

It is an arithmetic number, because the mean of its divisors is an integer number (1077565370112).

Almost surely, 2^{21356140633455} is an apocalyptic number.

21356140633455 is a deficient number, since it is larger than the sum of its proper divisors (13125951210129).

21356140633455 is a wasteful number, since it uses less digits than its factorization.

21356140633455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14066895.

The product of its (nonzero) digits is 3888000, while the sum is 48.

Adding to 21356140633455 its reverse (55433604165312), we get a palindrome (76789744798767).

The spelling of 21356140633455 in words is "twenty-one trillion, three hundred fifty-six billion, one hundred forty million, six hundred thirty-three thousand, four hundred fifty-five".