20891611453 has 2 divisors, whose sum is σ = 20891611454. Its totient is φ = 20891611452.

The previous prime is 20891611417. The next prime is 20891611483. The reversal of 20891611453 is 35411619802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11894519844 + 8997091609 = 109062^2 + 94853^2 .

It is a cyclic number.

It is not a de Polignac number, because 20891611453 - 2²⁹ = 20354740541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20891611483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10445805726 + 10445805727.

It is an arithmetic number, because the mean of its divisors is an integer number (10445805727).

Almost surely, 2^20891611453 is an apocalyptic number.

It is an amenable number.

20891611453 is a deficient number, since it is larger than the sum of its proper divisors (1).

20891611453 is an equidigital number, since it uses as much as digits as its factorization.

20891611453 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 40.

The spelling of 20891611453 in words is "twenty billion, eight hundred ninety-one million, six hundred eleven thousand, four hundred fifty-three".