21623393161 has 2 divisors, whose sum is σ = 21623393162. Its totient is φ = 21623393160.

The previous prime is 21623393119. The next prime is 21623393171. The reversal of 21623393161 is 16139332612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12809938761 + 8813454400 = 113181^2 + 93880^2 .

It is a cyclic number.

It is not a de Polignac number, because 21623393161 - 2¹¹ = 21623391113 is a prime.

It is a super-2 number, since 2×21623393161² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21623393161.

It is not a weakly prime, because it can be changed into another prime (21623393171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10811696580 + 10811696581.

It is an arithmetic number, because the mean of its divisors is an integer number (10811696581).

Almost surely, 2^21623393161 is an apocalyptic number.

It is an amenable number.

21623393161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21623393161 is an equidigital number, since it uses as much as digits as its factorization.

21623393161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 37.

The spelling of 21623393161 in words is "twenty-one billion, six hundred twenty-three million, three hundred ninety-three thousand, one hundred sixty-one".