20674921 has 2 divisors, whose sum is σ = 20674922. Its totient is φ = 20674920.

The previous prime is 20674919. The next prime is 20674931. The reversal of 20674921 is 12947602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19900521 + 774400 = 4461^2 + 880^2 .

It is a cyclic number.

It is not a de Polignac number, because 20674921 - 2¹ = 20674919 is a prime.

Together with 20674919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20674931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10337460 + 10337461.

It is an arithmetic number, because the mean of its divisors is an integer number (10337461).

Almost surely, 2^20674921 is an apocalyptic number.

It is an amenable number.

20674921 is a deficient number, since it is larger than the sum of its proper divisors (1).

20674921 is an equidigital number, since it uses as much as digits as its factorization.

20674921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20674921 is about 4546.9683306573. The cubic root of 20674921 is about 274.4614075536.

The spelling of 20674921 in words is "twenty million, six hundred seventy-four thousand, nine hundred twenty-one".