21753446987 has 2 divisors, whose sum is σ = 21753446988. Its totient is φ = 21753446986.

The previous prime is 21753446983. The next prime is 21753447029. The reversal of 21753446987 is 78964435712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21753446987 - 2² = 21753446983 is a prime.

It is not a weakly prime, because it can be changed into another prime (21753446983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10876723493 + 10876723494.

It is an arithmetic number, because the mean of its divisors is an integer number (10876723494).

Almost surely, 2^21753446987 is an apocalyptic number.

21753446987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21753446987 is an equidigital number, since it uses as much as digits as its factorization.

21753446987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10160640, while the sum is 56.

The spelling of 21753446987 in words is "twenty-one billion, seven hundred fifty-three million, four hundred forty-six thousand, nine hundred eighty-seven".