21521600115551 has 8 divisors (see below), whose sum is σ = 21554590815120. Its totient is φ = 21488621450688.

The previous prime is 21521600115503. The next prime is 21521600115557. The reversal of 21521600115551 is 15551100612512.

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 21521600115551 - 2¹⁸ = 21521599853407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21521600115557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 573920 + ... + 6585786.

It is an arithmetic number, because the mean of its divisors is an integer number (2694323851890).

Almost surely, 2^{21521600115551} is an apocalyptic number.

21521600115551 is a deficient number, since it is larger than the sum of its proper divisors (32990699569).

21521600115551 is an equidigital number, since it uses as much as digits as its factorization.

21521600115551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6017353.

The product of its (nonzero) digits is 15000, while the sum is 35.

The spelling of 21521600115551 in words is "twenty-one trillion, five hundred twenty-one billion, six hundred million, one hundred fifteen thousand, five hundred fifty-one".