21211252315 has 8 divisors (see below), whose sum is σ = 27767457648. Its totient is φ = 15426365280.

The previous prime is 21211252301. The next prime is 21211252369. The reversal of 21211252315 is 51325211212.

It is a happy number.

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

It is not a de Polignac number, because 21211252315 - 2²⁵ = 21177697883 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21211252315.

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, 192829512 + ... + 192829621.

It is an arithmetic number, because the mean of its divisors is an integer number (3470932206).

Almost surely, 2^21211252315 is an apocalyptic number.

21211252315 is a deficient number, since it is larger than the sum of its proper divisors (6556205333).

21211252315 is a wasteful number, since it uses less digits than its factorization.

21211252315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385659149.

The product of its digits is 1200, while the sum is 25.

Adding to 21211252315 its reverse (51325211212), we get a palindrome (72536463527).

The spelling of 21211252315 in words is "twenty-one billion, two hundred eleven million, two hundred fifty-two thousand, three hundred fifteen".