21151214880 has 48 divisors (see below), whose sum is σ = 66626328384. Its totient is φ = 5640323840.

The previous prime is 21151214839. The next prime is 21151214893. The reversal of 21151214880 is 8841215112.

It is a tau number, because it is divible by the number of its divisors (48).

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

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, 22032036 + ... + 22032995.

It is an arithmetic number, because the mean of its divisors is an integer number (1388048508).

Almost surely, 2^21151214880 is an apocalyptic number.

21151214880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21151214880 is an abundant number, since it is smaller than the sum of its proper divisors (45475113504).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21151214880 is a wasteful number, since it uses less digits than its factorization.

21151214880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44065049 (or 44065041 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 33.

Adding to 21151214880 its reverse (8841215112), we get a palindrome (29992429992).

The spelling of 21151214880 in words is "twenty-one billion, one hundred fifty-one million, two hundred fourteen thousand, eight hundred eighty".