21661042026253 has 16 divisors (see below), whose sum is σ = 26351187408000. Its totient is φ = 17391783670272.

The previous prime is 21661042026199. The next prime is 21661042026277. The reversal of 21661042026253 is 35262024016612.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21661042026253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21661042023253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 914959948 + ... + 914983621.

It is an arithmetic number, because the mean of its divisors is an integer number (1646949213000).

Almost surely, 2^{21661042026253} is an apocalyptic number.

It is an amenable number.

21661042026253 is a deficient number, since it is larger than the sum of its proper divisors (4690145381747).

21661042026253 is a wasteful number, since it uses less digits than its factorization.

21661042026253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1829943684.

The product of its (nonzero) digits is 207360, while the sum is 40.

The spelling of 21661042026253 in words is "twenty-one trillion, six hundred sixty-one billion, forty-two million, twenty-six thousand, two hundred fifty-three".