21623393461 has 2 divisors, whose sum is σ = 21623393462. Its totient is φ = 21623393460.

The previous prime is 21623393419. The next prime is 21623393501. The reversal of 21623393461 is 16439332612.

It is an a-pointer prime, because the next prime (21623393501) can be obtained adding 21623393461 to its sum of digits (40).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13134535236 + 8488858225 = 114606^2 + 92135^2 .

It is a cyclic number.

It is not a de Polignac number, because 21623393461 - 2⁷ = 21623393333 is a prime.

It is a super-2 number, since 2×21623393461² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21623393161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10811696730 + 10811696731.

It is an arithmetic number, because the mean of its divisors is an integer number (10811696731).

Almost surely, 2^21623393461 is an apocalyptic number.

It is an amenable number.

21623393461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21623393461 is an equidigital number, since it uses as much as digits as its factorization.

21623393461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 40.

The spelling of 21623393461 in words is "twenty-one billion, six hundred twenty-three million, three hundred ninety-three thousand, four hundred sixty-one".