21267384731 has 8 divisors (see below), whose sum is σ = 21541143600. Its totient is φ = 20994399360.

The previous prime is 21267384667. The next prime is 21267384757. The reversal of 21267384731 is 13748376212.

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 21267384731 - 2⁶ = 21267384667 is a prime.

It is a super-2 number, since 2×21267384731² (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 (21267384781) 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, 137930 + ... + 248111.

It is an arithmetic number, because the mean of its divisors is an integer number (2692642950).

Almost surely, 2^21267384731 is an apocalyptic number.

21267384731 is a deficient number, since it is larger than the sum of its proper divisors (273758869).

21267384731 is an equidigital number, since it uses as much as digits as its factorization.

21267384731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386749.

The product of its digits is 338688, while the sum is 44.

The spelling of 21267384731 in words is "twenty-one billion, two hundred sixty-seven million, three hundred eighty-four thousand, seven hundred thirty-one".