21557496383 has 4 divisors (see below), whose sum is σ = 21607514208. Its totient is φ = 21507478560.

The previous prime is 21557496353. The next prime is 21557496397. The reversal of 21557496383 is 38369475512.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21557496383 - 2¹⁸ = 21557234239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21557496353) 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, 25008266 + ... + 25009127.

It is an arithmetic number, because the mean of its divisors is an integer number (5401878552).

Almost surely, 2^21557496383 is an apocalyptic number.

21557496383 is a deficient number, since it is larger than the sum of its proper divisors (50017825).

21557496383 is an equidigital number, since it uses as much as digits as its factorization.

21557496383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50017824.

The product of its digits is 5443200, while the sum is 53.

The spelling of 21557496383 in words is "twenty-one billion, five hundred fifty-seven million, four hundred ninety-six thousand, three hundred eighty-three".