21234777661021 has 8 divisors (see below), whose sum is σ = 22089732112800. Its totient is φ = 20388004591920.

The previous prime is 21234777661001. The next prime is 21234777661127. The reversal of 21234777661021 is 12016677743212.

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 21234777661021 - 2⁵ = 21234777660989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21234777661001) 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, 2045340375 + ... + 2045350756.

It is an arithmetic number, because the mean of its divisors is an integer number (2761216514100).

Almost surely, 2^{21234777661021} is an apocalyptic number.

It is an amenable number.

21234777661021 is a deficient number, since it is larger than the sum of its proper divisors (854954451779).

21234777661021 is a wasteful number, since it uses less digits than its factorization.

21234777661021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4090691339.

The product of its (nonzero) digits is 1185408, while the sum is 49.

The spelling of 21234777661021 in words is "twenty-one trillion, two hundred thirty-four billion, seven hundred seventy-seven million, six hundred sixty-one thousand, twenty-one".