21551470416 has 100 divisors (see below), whose sum is σ = 71287124832. Its totient is φ = 6157560384.

The previous prime is 21551470337. The next prime is 21551470459. The reversal of 21551470416 is 61407415512.

21551470416 is a `hidden beast` number, since 21 + 551 + 4 + 70 + 4 + 16 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1178730 + ... + 1196873.

Almost surely, 2^21551470416 is an apocalyptic number.

It is an amenable number.

21551470416 is an abundant number, since it is smaller than the sum of its proper divisors (49735654416).

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

21551470416 is a wasteful number, since it uses less digits than its factorization.

21551470416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2375630 (or 2375615 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

Adding to 21551470416 its reverse (61407415512), we get a palindrome (82958885928).

The spelling of 21551470416 in words is "twenty-one billion, five hundred fifty-one million, four hundred seventy thousand, four hundred sixteen".