21940951489 has 2 divisors, whose sum is σ = 21940951490. Its totient is φ = 21940951488.

The previous prime is 21940951397. The next prime is 21940951511. The reversal of 21940951489 is 98415904912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21923244225 + 17707264 = 148065^2 + 4208^2 .

It is a cyclic number.

It is not a de Polignac number, because 21940951489 - 2¹⁵ = 21940918721 is a prime.

It is not a weakly prime, because it can be changed into another prime (21940951589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10970475744 + 10970475745.

It is an arithmetic number, because the mean of its divisors is an integer number (10970475745).

Almost surely, 2^21940951489 is an apocalyptic number.

It is an amenable number.

21940951489 is a deficient number, since it is larger than the sum of its proper divisors (1).

21940951489 is an equidigital number, since it uses as much as digits as its factorization.

21940951489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 933120, while the sum is 52.

The spelling of 21940951489 in words is "twenty-one billion, nine hundred forty million, nine hundred fifty-one thousand, four hundred eighty-nine".