21012423007 has 16 divisors (see below), whose sum is σ = 22841026560. Its totient is φ = 19271973600.

The previous prime is 21012423001. The next prime is 21012423013. The reversal of 21012423007 is 70032421012.

It is an interprime number because it is at equal distance from previous prime (21012423001) and next prime (21012423013).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012423007 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 (21012423001) 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, 57469 + ... + 212902.

It is an arithmetic number, because the mean of its divisors is an integer number (1427564160).

Almost surely, 2^21012423007 is an apocalyptic number.

21012423007 is a deficient number, since it is larger than the sum of its proper divisors (1828603553).

21012423007 is a wasteful number, since it uses less digits than its factorization.

21012423007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270534.

The product of its (nonzero) digits is 672, while the sum is 22.

Adding to 21012423007 its reverse (70032421012), we get a palindrome (91044844019).

The spelling of 21012423007 in words is "twenty-one billion, twelve million, four hundred twenty-three thousand, seven".