21264212707 has 4 divisors (see below), whose sum is σ = 21265310896. Its totient is φ = 21263114520.

The previous prime is 21264212699. The next prime is 21264212719. The reversal of 21264212707 is 70721246212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21264212707 - 2³ = 21264212699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21264212737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 519519 + ... + 558952.

It is an arithmetic number, because the mean of its divisors is an integer number (5316327724).

Almost surely, 2^21264212707 is an apocalyptic number.

21264212707 is a deficient number, since it is larger than the sum of its proper divisors (1098189).

21264212707 is a wasteful number, since it uses less digits than its factorization.

21264212707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1098188.

The product of its (nonzero) digits is 18816, while the sum is 34.

Adding to 21264212707 its reverse (70721246212), we get a palindrome (91985458919).

The spelling of 21264212707 in words is "twenty-one billion, two hundred sixty-four million, two hundred twelve thousand, seven hundred seven".