21012451023 has 8 divisors (see below), whose sum is σ = 28018603648. Its totient is φ = 14007299544.

The previous prime is 21012451007. The next prime is 21012451049. The reversal of 21012451023 is 32015421012.

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

It is not a de Polignac number, because 21012451023 - 2⁴ = 21012451007 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012451003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 199861 + ... + 286302.

It is an arithmetic number, because the mean of its divisors is an integer number (3502325456).

Almost surely, 2^21012451023 is an apocalyptic number.

21012451023 is a deficient number, since it is larger than the sum of its proper divisors (7006152625).

21012451023 is a wasteful number, since it uses less digits than its factorization.

21012451023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500573.

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21012451023 its reverse (32015421012), we get a palindrome (53027872035).

The spelling of 21012451023 in words is "twenty-one billion, twelve million, four hundred fifty-one thousand, twenty-three".