21553741766 has 16 divisors (see below), whose sum is σ = 32387433984. Its totient is φ = 10757949384.

The previous prime is 21553741739. The next prime is 21553741789. The reversal of 21553741766 is 66714735512.

It is a self number, because there is not a number n which added to its sum of digits gives 21553741766.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3083111 + ... + 3090093.

It is an arithmetic number, because the mean of its divisors is an integer number (2024214624).

Almost surely, 2^21553741766 is an apocalyptic number.

21553741766 is a deficient number, since it is larger than the sum of its proper divisors (10833692218).

21553741766 is a wasteful number, since it uses less digits than its factorization.

21553741766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9475.

The product of its digits is 1058400, while the sum is 47.

The spelling of 21553741766 in words is "twenty-one billion, five hundred fifty-three million, seven hundred forty-one thousand, seven hundred sixty-six".