21642950015 has 16 divisors (see below), whose sum is σ = 26690938560. Its totient is φ = 16835374080.

The previous prime is 21642949981. The next prime is 21642950023. The reversal of 21642950015 is 51005924612.

It is a happy number.

It is not a de Polignac number, because 21642950015 - 2¹⁶ = 21642884479 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 250895 + ... + 325935.

It is an arithmetic number, because the mean of its divisors is an integer number (1668183660).

Almost surely, 2^21642950015 is an apocalyptic number.

21642950015 is a deficient number, since it is larger than the sum of its proper divisors (5047988545).

21642950015 is a wasteful number, since it uses less digits than its factorization.

21642950015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76642.

The product of its (nonzero) digits is 21600, while the sum is 35.

The spelling of 21642950015 in words is "twenty-one billion, six hundred forty-two million, nine hundred fifty thousand, fifteen".