21551470415 has 8 divisors (see below), whose sum is σ = 25866063600. Its totient is φ = 17238310272.

The previous prime is 21551470337. The next prime is 21551470459. The reversal of 21551470415 is 51407415512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21551470415 - 2²⁰ = 21550421839 is a prime.

It is a congruent number.

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, 324890 + ... + 385559.

It is an arithmetic number, because the mean of its divisors is an integer number (3233257950).

Almost surely, 2^21551470415 is an apocalyptic number.

21551470415 is a deficient number, since it is larger than the sum of its proper divisors (4314593185).

21551470415 is an equidigital number, since it uses as much as digits as its factorization.

21551470415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716521.

The product of its (nonzero) digits is 28000, while the sum is 35.

Adding to 21551470415 its reverse (51407415512), we get a palindrome (72958885927).

The spelling of 21551470415 in words is "twenty-one billion, five hundred fifty-one million, four hundred seventy thousand, four hundred fifteen".