21447834515 has 16 divisors (see below), whose sum is σ = 26409753216. Its totient is φ = 16711449600.

The previous prime is 21447834503. The next prime is 21447834517. The reversal of 21447834515 is 51543874412.

It is a happy number.

It is not a de Polignac number, because 21447834515 - 2⁶ = 21447834451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21447834517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33350 + ... + 209780.

It is an arithmetic number, because the mean of its divisors is an integer number (1650609576).

Almost surely, 2^21447834515 is an apocalyptic number.

21447834515 is a deficient number, since it is larger than the sum of its proper divisors (4961918701).

21447834515 is a wasteful number, since it uses less digits than its factorization.

21447834515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177070.

The product of its digits is 537600, while the sum is 44.

The spelling of 21447834515 in words is "twenty-one billion, four hundred forty-seven million, eight hundred thirty-four thousand, five hundred fifteen".