21516151120501 has 4 divisors (see below), whose sum is σ = 21737967111532. Its totient is φ = 21294335129472.

The previous prime is 21516151120489. The next prime is 21516151120523. The reversal of 21516151120501 is 10502115161512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17552966019876 + 3963185100625 = 4189626^2 + 1990775^2 .

It is a cyclic number.

It is not a de Polignac number, because 21516151120501 - 2¹⁷ = 21516150989429 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 (21516151100501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110907995370 + ... + 110907995563.

It is an arithmetic number, because the mean of its divisors is an integer number (5434491777883).

Almost surely, 2^{21516151120501} is an apocalyptic number.

It is an amenable number.

21516151120501 is a deficient number, since it is larger than the sum of its proper divisors (221815991031).

21516151120501 is an equidigital number, since it uses as much as digits as its factorization.

21516151120501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221815991030.

The product of its (nonzero) digits is 3000, while the sum is 31.

The spelling of 21516151120501 in words is "twenty-one trillion, five hundred sixteen billion, one hundred fifty-one million, one hundred twenty thousand, five hundred one".