21357262123 has 8 divisors (see below), whose sum is σ = 21412723248. Its totient is φ = 21301830144.

The previous prime is 21357262097. The next prime is 21357262133. The reversal of 21357262123 is 32126275312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21357262123 is a prime.

It is a super-2 number, since 2×21357262123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21357262133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2705340 + ... + 2713222.

It is an arithmetic number, because the mean of its divisors is an integer number (2676590406).

Almost surely, 2^21357262123 is an apocalyptic number.

21357262123 is a deficient number, since it is larger than the sum of its proper divisors (55461125).

21357262123 is an equidigital number, since it uses as much as digits as its factorization.

21357262123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14573.

The product of its digits is 30240, while the sum is 34.

The spelling of 21357262123 in words is "twenty-one billion, three hundred fifty-seven million, two hundred sixty-two thousand, one hundred twenty-three".