21516131540351 has 4 divisors (see below), whose sum is σ = 24589864617552. Its totient is φ = 18442398463152.

The previous prime is 21516131540311. The next prime is 21516131540369. The reversal of 21516131540351 is 15304513161512.

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

It is a cyclic number.

It is not a de Polignac number, because 21516131540351 - 2⁶ = 21516131540287 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 (21516131540311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1536866538590 + ... + 1536866538603.

It is an arithmetic number, because the mean of its divisors is an integer number (6147466154388).

Almost surely, 2^{21516131540351} is an apocalyptic number.

21516131540351 is a deficient number, since it is larger than the sum of its proper divisors (3073733077201).

21516131540351 is an equidigital number, since it uses as much as digits as its factorization.

21516131540351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3073733077200.

The product of its (nonzero) digits is 54000, while the sum is 38.

The spelling of 21516131540351 in words is "twenty-one trillion, five hundred sixteen billion, one hundred thirty-one million, five hundred forty thousand, three hundred fifty-one".