21545225345251 has 8 divisors (see below), whose sum is σ = 21599660898144. Its totient is φ = 21490855026240.

The previous prime is 21545225345207. The next prime is 21545225345257. The reversal of 21545225345251 is 15254352254512.

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 21545225345251 - 2²³ = 21545216956643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21545225345257) 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, 15647050 + ... + 16968223.

It is an arithmetic number, because the mean of its divisors is an integer number (2699957612268).

Almost surely, 2^{21545225345251} is an apocalyptic number.

21545225345251 is a deficient number, since it is larger than the sum of its proper divisors (54435552893).

21545225345251 is a wasteful number, since it uses less digits than its factorization.

21545225345251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32616941.

The product of its digits is 2400000, while the sum is 46.

Adding to 21545225345251 its reverse (15254352254512), we get a palindrome (36799577599763).

The spelling of 21545225345251 in words is "twenty-one trillion, five hundred forty-five billion, two hundred twenty-five million, three hundred forty-five thousand, two hundred fifty-one".