21415145553 has 32 divisors (see below), whose sum is σ = 32199235200. Its totient is φ = 14240577600.

The previous prime is 21415145491. The next prime is 21415145561. The reversal of 21415145553 is 35554151412.

21415145553 is a `hidden beast` number, since 2 + 1 + 4 + 151 + 455 + 53 = 666.

It is not a de Polignac number, because 21415145553 - 2¹² = 21415141457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21415143553) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 864778 + ... + 889196.

It is an arithmetic number, because the mean of its divisors is an integer number (1006226100).

Almost surely, 2^21415145553 is an apocalyptic number.

It is an amenable number.

21415145553 is a deficient number, since it is larger than the sum of its proper divisors (10784089647).

21415145553 is an frugal number, since it uses more digits than its factorization.

21415145553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24841 (or 24823 counting only the distinct ones).

The product of its digits is 60000, while the sum is 36.

Adding to 21415145553 its reverse (35554151412), we get a palindrome (56969296965).

The spelling of 21415145553 in words is "twenty-one billion, four hundred fifteen million, one hundred forty-five thousand, five hundred fifty-three".