21491914939 has 8 divisors (see below), whose sum is σ = 23481311040. Its totient is φ = 19508449800.

The previous prime is 21491914931. The next prime is 21491914943. The reversal of 21491914939 is 93941919412.

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

It is a cyclic number.

It is not a de Polignac number, because 21491914939 - 2³ = 21491914931 is a prime.

It is a super-2 number, since 2×21491914939² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21491914931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1475157 + ... + 1489654.

It is an arithmetic number, because the mean of its divisors is an integer number (2935163880).

Almost surely, 2^21491914939 is an apocalyptic number.

21491914939 is a deficient number, since it is larger than the sum of its proper divisors (1989396101).

21491914939 is a wasteful number, since it uses less digits than its factorization.

21491914939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2965481.

The product of its digits is 629856, while the sum is 52.

The spelling of 21491914939 in words is "twenty-one billion, four hundred ninety-one million, nine hundred fourteen thousand, nine hundred thirty-nine".