21676553 has 2 divisors, whose sum is σ = 21676554. Its totient is φ = 21676552.

The previous prime is 21676537. The next prime is 21676579. The reversal of 21676553 is 35567612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16418704 + 5257849 = 4052^2 + 2293^2 .

It is a cyclic number.

It is not a de Polignac number, because 21676553 - 2⁴ = 21676537 is a prime.

It is not a weakly prime, because it can be changed into another prime (21675553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10838276 + 10838277.

It is an arithmetic number, because the mean of its divisors is an integer number (10838277).

Almost surely, 2^21676553 is an apocalyptic number.

It is an amenable number.

21676553 is a deficient number, since it is larger than the sum of its proper divisors (1).

21676553 is an equidigital number, since it uses as much as digits as its factorization.

21676553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37800, while the sum is 35.

The square root of 21676553 is about 4655.8085226951. The cubic root of 21676553 is about 278.8239490909.

The spelling of 21676553 in words is "twenty-one million, six hundred seventy-six thousand, five hundred fifty-three".