21500344156 has 12 divisors (see below), whose sum is σ = 39261498192. Its totient is φ = 10282773248.

The previous prime is 21500344139. The next prime is 21500344183. The reversal of 21500344156 is 65144300512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116849605 + ... + 116849788.

It is an arithmetic number, because the mean of its divisors is an integer number (3271791516).

Almost surely, 2^21500344156 is an apocalyptic number.

It is an amenable number.

21500344156 is a deficient number, since it is larger than the sum of its proper divisors (17761154036).

21500344156 is a wasteful number, since it uses less digits than its factorization.

21500344156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233699420 (or 233699418 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

Adding to 21500344156 its reverse (65144300512), we get a palindrome (86644644668).

The spelling of 21500344156 in words is "twenty-one billion, five hundred million, three hundred forty-four thousand, one hundred fifty-six".