21502543515155 has 8 divisors (see below), whose sum is σ = 25804079683152. Its totient is φ = 17201349835488.

The previous prime is 21502543515149. The next prime is 21502543515179. The reversal of 21502543515155 is 55151534520512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21502543515155 - 2⁴ = 21502543515139 is a prime.

It is a super-2 number, since 2×21502543515155² (a number of 27 digits) contains 22 as substring.

It is a Duffinian 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, 85483937 + ... + 85735106.

It is an arithmetic number, because the mean of its divisors is an integer number (3225509960394).

Almost surely, 2^{21502543515155} is an apocalyptic number.

21502543515155 is a deficient number, since it is larger than the sum of its proper divisors (4301536167997).

21502543515155 is a wasteful number, since it uses less digits than its factorization.

21502543515155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171244165.

The product of its (nonzero) digits is 750000, while the sum is 44.

The spelling of 21502543515155 in words is "twenty-one trillion, five hundred two billion, five hundred forty-three million, five hundred fifteen thousand, one hundred fifty-five".