21745982707 has 4 divisors (see below), whose sum is σ = 22691460240. Its totient is φ = 20800505176.

The previous prime is 21745982693. The next prime is 21745982711. The reversal of 21745982707 is 70728954712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21745982707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21745982767) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 472738732 + ... + 472738777.

It is an arithmetic number, because the mean of its divisors is an integer number (5672865060).

Almost surely, 2^21745982707 is an apocalyptic number.

21745982707 is a deficient number, since it is larger than the sum of its proper divisors (945477533).

21745982707 is an equidigital number, since it uses as much as digits as its factorization.

21745982707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 945477532.

The product of its (nonzero) digits is 1975680, while the sum is 52.

The spelling of 21745982707 in words is "twenty-one billion, seven hundred forty-five million, nine hundred eighty-two thousand, seven hundred seven".