21119948977 has 2 divisors, whose sum is σ = 21119948978. Its totient is φ = 21119948976.

The previous prime is 21119948951. The next prime is 21119948989. The reversal of 21119948977 is 77984991112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21002096241 + 117852736 = 144921^2 + 10856^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21119948977 is a prime.

It is not a weakly prime, because it can be changed into another prime (21119948177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10559974488 + 10559974489.

It is an arithmetic number, because the mean of its divisors is an integer number (10559974489).

Almost surely, 2^21119948977 is an apocalyptic number.

It is an amenable number.

21119948977 is a deficient number, since it is larger than the sum of its proper divisors (1).

21119948977 is an equidigital number, since it uses as much as digits as its factorization.

21119948977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2286144, while the sum is 58.

The spelling of 21119948977 in words is "twenty-one billion, one hundred nineteen million, nine hundred forty-eight thousand, nine hundred seventy-seven".