21125151113 has 16 divisors (see below), whose sum is σ = 24206902272. Its totient is φ = 18248010000.

The previous prime is 21125151109. The next prime is 21125151127. The reversal of 21125151113 is 31115152112.

It is not a de Polignac number, because 21125151113 - 2² = 21125151109 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21125151143) 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, 238283 + ... + 314688.

It is an arithmetic number, because the mean of its divisors is an integer number (1512931392).

Almost surely, 2^21125151113 is an apocalyptic number.

21125151113 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21125151113 is a deficient number, since it is larger than the sum of its proper divisors (3081751159).

21125151113 is a wasteful number, since it uses less digits than its factorization.

21125151113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553156.

The product of its digits is 300, while the sum is 23.

Subtracting 21125151113 from its reverse (31115152112), we obtain a palindrome (9990000999).

The spelling of 21125151113 in words is "twenty-one billion, one hundred twenty-five million, one hundred fifty-one thousand, one hundred thirteen".