21517147251403 has 8 divisors (see below), whose sum is σ = 21664058668560. Its totient is φ = 21370734685440.

The previous prime is 21517147251389. The next prime is 21517147251461. The reversal of 21517147251403 is 30415274171512.

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 21517147251403 - 2¹⁷ = 21517147120331 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21517147251403.

It is not an unprimeable number, because it can be changed into a prime (21517147251463) 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, 124626238 + ... + 124798771.

It is an arithmetic number, because the mean of its divisors is an integer number (2708007333570).

Almost surely, 2^{21517147251403} is an apocalyptic number.

21517147251403 is a deficient number, since it is larger than the sum of its proper divisors (146911417157).

21517147251403 is a wasteful number, since it uses less digits than its factorization.

21517147251403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249425597.

The product of its (nonzero) digits is 235200, while the sum is 43.

The spelling of 21517147251403 in words is "twenty-one trillion, five hundred seventeen billion, one hundred forty-seven million, two hundred fifty-one thousand, four hundred three".