21355160647 has 4 divisors (see below), whose sum is σ = 21673894456. Its totient is φ = 21036426840.

The previous prime is 21355160579. The next prime is 21355160669. The reversal of 21355160647 is 74606155312.

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

It is not a de Polignac number, because 21355160647 - 2²³ = 21346772039 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 (21355160677) 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, 159366804 + ... + 159366937.

It is an arithmetic number, because the mean of its divisors is an integer number (5418473614).

Almost surely, 2^21355160647 is an apocalyptic number.

21355160647 is a deficient number, since it is larger than the sum of its proper divisors (318733809).

21355160647 is an equidigital number, since it uses as much as digits as its factorization.

21355160647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318733808.

The product of its (nonzero) digits is 151200, while the sum is 40.

The spelling of 21355160647 in words is "twenty-one billion, three hundred fifty-five million, one hundred sixty thousand, six hundred forty-seven".