21387263723 has 8 divisors (see below), whose sum is σ = 25231057920. Its totient is φ = 17740587240.

The previous prime is 21387263717. The next prime is 21387263731. The reversal of 21387263723 is 32736278312.

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 21387263723 - 2⁴ = 21387263707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21387263783) 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, 49279193 + ... + 49279626.

It is an arithmetic number, because the mean of its divisors is an integer number (3153882240).

Almost surely, 2^21387263723 is an apocalyptic number.

21387263723 is a deficient number, since it is larger than the sum of its proper divisors (3843794197).

21387263723 is an equidigital number, since it uses as much as digits as its factorization.

21387263723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98558857.

The product of its digits is 508032, while the sum is 44.

The spelling of 21387263723 in words is "twenty-one billion, three hundred eighty-seven million, two hundred sixty-three thousand, seven hundred twenty-three".