21813040723 has 2 divisors, whose sum is σ = 21813040724. Its totient is φ = 21813040722.

The previous prime is 21813040709. The next prime is 21813040727. The reversal of 21813040723 is 32704031812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21813040723 - 2¹³ = 21813032531 is a prime.

It is not a weakly prime, because it can be changed into another prime (21813040727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10906520361 + 10906520362.

It is an arithmetic number, because the mean of its divisors is an integer number (10906520362).

Almost surely, 2^21813040723 is an apocalyptic number.

21813040723 is a deficient number, since it is larger than the sum of its proper divisors (1).

21813040723 is an equidigital number, since it uses as much as digits as its factorization.

21813040723 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 31.

The spelling of 21813040723 in words is "twenty-one billion, eight hundred thirteen million, forty thousand, seven hundred twenty-three".