21454613 has 2 divisors, whose sum is σ = 21454614. Its totient is φ = 21454612.

The previous prime is 21454547. The next prime is 21454621. The reversal of 21454613 is 31645412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13490929 + 7963684 = 3673^2 + 2822^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21454613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21454813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10727306 + 10727307.

It is an arithmetic number, because the mean of its divisors is an integer number (10727307).

Almost surely, 2^21454613 is an apocalyptic number.

It is an amenable number.

21454613 is a deficient number, since it is larger than the sum of its proper divisors (1).

21454613 is an equidigital number, since it uses as much as digits as its factorization.

21454613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 26.

The square root of 21454613 is about 4631.9124559948. The cubic root of 21454613 is about 277.8690833298.

The spelling of 21454613 in words is "twenty-one million, four hundred fifty-four thousand, six hundred thirteen".