21001907969 has 4 divisors (see below), whose sum is σ = 24002180544. Its totient is φ = 18001635396.

The previous prime is 21001907951. The next prime is 21001907977. The reversal of 21001907969 is 96970910012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21001907969 - 2²⁴ = 20985130753 is a prime.

It is a super-2 number, since 2×21001907969² (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 (21001907939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1500136277 + ... + 1500136290.

It is an arithmetic number, because the mean of its divisors is an integer number (6000545136).

Almost surely, 2^21001907969 is an apocalyptic number.

It is an amenable number.

21001907969 is a deficient number, since it is larger than the sum of its proper divisors (3000272575).

21001907969 is an equidigital number, since it uses as much as digits as its factorization.

21001907969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3000272574.

The product of its (nonzero) digits is 61236, while the sum is 44.

The spelling of 21001907969 in words is "twenty-one billion, one million, nine hundred seven thousand, nine hundred sixty-nine".