21434453661021 has 16 divisors (see below), whose sum is σ = 28904377478400. Its totient is φ = 14127127148288.

The previous prime is 21434453661013. The next prime is 21434453661073. The reversal of 21434453661021 is 12016635443412.

It is a cyclic number.

It is not a de Polignac number, because 21434453661021 - 2³ = 21434453661013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21434453661221) 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, 3603816 + ... + 7473713.

It is an arithmetic number, because the mean of its divisors is an integer number (1806523592400).

Almost surely, 2^{21434453661021} is an apocalyptic number.

It is an amenable number.

21434453661021 is a deficient number, since it is larger than the sum of its proper divisors (7469923817379).

21434453661021 is a wasteful number, since it uses less digits than its factorization.

21434453661021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11084868.

The product of its (nonzero) digits is 414720, while the sum is 42.

The spelling of 21434453661021 in words is "twenty-one trillion, four hundred thirty-four billion, four hundred fifty-three million, six hundred sixty-one thousand, twenty-one".