21255601002601 has 48 divisors (see below), whose sum is σ = 25797961800192. Its totient is φ = 17142509416320.

The previous prime is 21255601002577. The next prime is 21255601002667. The reversal of 21255601002601 is 10620010655212.

It is not a de Polignac number, because 21255601002601 - 2²³ = 21255592613993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is not an unprimeable number, because it can be changed into a prime (21255601008601) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 354153271 + ... + 354213283.

It is an arithmetic number, because the mean of its divisors is an integer number (537457537504).

Almost surely, 2^{21255601002601} is an apocalyptic number.

It is an amenable number.

21255601002601 is a deficient number, since it is larger than the sum of its proper divisors (4542360797591).

21255601002601 is a wasteful number, since it uses less digits than its factorization.

21255601002601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61542 (or 61511 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 31.

Adding to 21255601002601 its reverse (10620010655212), we get a palindrome (31875611657813).

The spelling of 21255601002601 in words is "twenty-one trillion, two hundred fifty-five billion, six hundred one million, two thousand, six hundred one".