21015150055 has 4 divisors (see below), whose sum is σ = 25218180072. Its totient is φ = 16812120040.

The previous prime is 21015150047. The next prime is 21015150097. The reversal of 21015150055 is 55005151012.

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

It is not a de Polignac number, because 21015150055 - 2³ = 21015150047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2101515001 + ... + 2101515010.

It is an arithmetic number, because the mean of its divisors is an integer number (6304545018).

Almost surely, 2^21015150055 is an apocalyptic number.

21015150055 is a deficient number, since it is larger than the sum of its proper divisors (4203030017).

21015150055 is an equidigital number, since it uses as much as digits as its factorization.

21015150055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4203030016.

The product of its (nonzero) digits is 1250, while the sum is 25.

The spelling of 21015150055 in words is "twenty-one billion, fifteen million, one hundred fifty thousand, fifty-five".