21145252225355 has 16 divisors (see below), whose sum is σ = 25993352498400. Its totient is φ = 16503507114240.

The previous prime is 21145252225343. The next prime is 21145252225381. The reversal of 21145252225355 is 55352225254112.

It is not a de Polignac number, because 21145252225355 - 2³⁰ = 21144178483531 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54992156 + ... + 55375334.

It is an arithmetic number, because the mean of its divisors is an integer number (1624584531150).

Almost surely, 2^{21145252225355} is an apocalyptic number.

21145252225355 is a deficient number, since it is larger than the sum of its proper divisors (4848100273045).

21145252225355 is a wasteful number, since it uses less digits than its factorization.

21145252225355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 652414.

The product of its digits is 1200000, while the sum is 44.

Adding to 21145252225355 its reverse (55352225254112), we get a palindrome (76497477479467).

The spelling of 21145252225355 in words is "twenty-one trillion, one hundred forty-five billion, two hundred fifty-two million, two hundred twenty-five thousand, three hundred fifty-five".