23121509977 has 2 divisors, whose sum is σ = 23121509978. Its totient is φ = 23121509976.

The previous prime is 23121509959. The next prime is 23121510019. The reversal of 23121509977 is 77990512132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11746007641 + 11375502336 = 108379^2 + 106656^2 .

It is a cyclic number.

It is not a de Polignac number, because 23121509977 - 2¹⁵ = 23121477209 is a prime.

It is not a weakly prime, because it can be changed into another prime (23121506977) 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, 11560754988 + 11560754989.

It is an arithmetic number, because the mean of its divisors is an integer number (11560754989).

Almost surely, 2^23121509977 is an apocalyptic number.

It is an amenable number.

23121509977 is a deficient number, since it is larger than the sum of its proper divisors (1).

23121509977 is an equidigital number, since it uses as much as digits as its factorization.

23121509977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 238140, while the sum is 46.

The spelling of 23121509977 in words is "twenty-three billion, one hundred twenty-one million, five hundred nine thousand, nine hundred seventy-seven".