21255113145 has 32 divisors (see below), whose sum is σ = 39525258240. Its totient is φ = 9551931840.

The previous prime is 21255113123. The next prime is 21255113167. The reversal of 21255113145 is 54131155212.

It is an interprime number because it is at equal distance from previous prime (21255113123) and next prime (21255113167).

It is not a de Polignac number, because 21255113145 - 2⁶ = 21255113081 is a prime.

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, 1709311 + ... + 1721700.

It is an arithmetic number, because the mean of its divisors is an integer number (1235164320).

Almost surely, 2^21255113145 is an apocalyptic number.

It is an amenable number.

21255113145 is a deficient number, since it is larger than the sum of its proper divisors (18270145095).

21255113145 is a wasteful number, since it uses less digits than its factorization.

21255113145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3431085.

The product of its digits is 6000, while the sum is 30.

Adding to 21255113145 its reverse (54131155212), we get a palindrome (75386268357).

The spelling of 21255113145 in words is "twenty-one billion, two hundred fifty-five million, one hundred thirteen thousand, one hundred forty-five".