21146004555 has 16 divisors (see below), whose sum is σ = 36436192800. Its totient is φ = 10410340608.

The previous prime is 21146004553. The next prime is 21146004587. The reversal of 21146004555 is 55540064112.

It is not a de Polignac number, because 21146004555 - 2¹ = 21146004553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21146004553) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54220330 + ... + 54220719.

It is an arithmetic number, because the mean of its divisors is an integer number (2277262050).

Almost surely, 2^21146004555 is an apocalyptic number.

21146004555 is a deficient number, since it is larger than the sum of its proper divisors (15290188245).

21146004555 is a wasteful number, since it uses less digits than its factorization.

21146004555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108441070.

The product of its (nonzero) digits is 24000, while the sum is 33.

Adding to 21146004555 its reverse (55540064112), we get a palindrome (76686068667).

The spelling of 21146004555 in words is "twenty-one billion, one hundred forty-six million, four thousand, five hundred fifty-five".