21679753 has 2 divisors, whose sum is σ = 21679754. Its totient is φ = 21679752.

The previous prime is 21679739. The next prime is 21679769. The reversal of 21679753 is 35797612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12020089 + 9659664 = 3467^2 + 3108^2 .

It is a cyclic number.

It is not a de Polignac number, because 21679753 - 2⁹ = 21679241 is a prime.

It is not a weakly prime, because it can be changed into another prime (21679453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10839876 + 10839877.

It is an arithmetic number, because the mean of its divisors is an integer number (10839877).

Almost surely, 2^21679753 is an apocalyptic number.

It is an amenable number.

21679753 is a deficient number, since it is larger than the sum of its proper divisors (1).

21679753 is an equidigital number, since it uses as much as digits as its factorization.

21679753 is an evil number, because the sum of its binary digits is even.

The product of its digits is 79380, while the sum is 40.

The square root of 21679753 is about 4656.1521667574. The cubic root of 21679753 is about 278.8376688727.

It can be divided in two parts, 2167 and 9753, that multiplied together give a triangular number (21134751 = T₆₅₀₁).

The spelling of 21679753 in words is "twenty-one million, six hundred seventy-nine thousand, seven hundred fifty-three".