215721010115 has 16 divisors (see below), whose sum is σ = 280389368448. Its totient is φ = 158380841856.

The previous prime is 215721010097. The next prime is 215721010139. The reversal of 215721010115 is 511010127512.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215721010115 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9580619 + ... + 9603108.

It is an arithmetic number, because the mean of its divisors is an integer number (17524335528).

Almost surely, 2^215721010115 is an apocalyptic number.

215721010115 is a deficient number, since it is larger than the sum of its proper divisors (64668358333).

215721010115 is a wasteful number, since it uses less digits than its factorization.

215721010115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19183918.

The product of its (nonzero) digits is 700, while the sum is 26.

Adding to 215721010115 its reverse (511010127512), we get a palindrome (726731137627).

The spelling of 215721010115 in words is "two hundred fifteen billion, seven hundred twenty-one million, ten thousand, one hundred fifteen".