21515420155039 has 4 divisors (see below), whose sum is σ = 21880088293320. Its totient is φ = 21150752016760.

The previous prime is 21515420155003. The next prime is 21515420155069. The reversal of 21515420155039 is 93055102451512.

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 21515420155039 - 2²⁹ = 21514883284127 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21515420154986 and 21515420155004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515420155069) 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, 182334069052 + ... + 182334069169.

It is an arithmetic number, because the mean of its divisors is an integer number (5470022073330).

Almost surely, 2^{21515420155039} is an apocalyptic number.

21515420155039 is a deficient number, since it is larger than the sum of its proper divisors (364668138281).

21515420155039 is an equidigital number, since it uses as much as digits as its factorization.

21515420155039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364668138280.

The product of its (nonzero) digits is 270000, while the sum is 43.

The spelling of 21515420155039 in words is "twenty-one trillion, five hundred fifteen billion, four hundred twenty million, one hundred fifty-five thousand, thirty-nine".