21960023 has 2 divisors, whose sum is σ = 21960024. Its totient is φ = 21960022.

The previous prime is 21960013. The next prime is 21960049. The reversal of 21960023 is 32006912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21960023 - 2⁴ = 21960007 is a prime.

It is a super-2 number, since 2×21960023² = 964485220321058, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21960013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10980011 + 10980012.

It is an arithmetic number, because the mean of its divisors is an integer number (10980012).

Almost surely, 2^21960023 is an apocalyptic number.

21960023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21960023 is an equidigital number, since it uses as much as digits as its factorization.

21960023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 21960023 is about 4686.1522595835. The cubic root of 21960023 is about 280.0341072397.

Adding to 21960023 its reverse (32006912), we get a palindrome (53966935).

The spelling of 21960023 in words is "twenty-one million, nine hundred sixty thousand, twenty-three".