20974691 has 2 divisors, whose sum is σ = 20974692. Its totient is φ = 20974690.

The previous prime is 20974687. The next prime is 20974741. The reversal of 20974691 is 19647902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20974691 - 2² = 20974687 is a prime.

It is not a weakly prime, because it can be changed into another prime (20979691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10487345 + 10487346.

It is an arithmetic number, because the mean of its divisors is an integer number (10487346).

Almost surely, 2^20974691 is an apocalyptic number.

20974691 is a deficient number, since it is larger than the sum of its proper divisors (1).

20974691 is an equidigital number, since it uses as much as digits as its factorization.

20974691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 38.

The square root of 20974691 is about 4579.8134241473. The cubic root of 20974691 is about 275.7815387781.

The spelling of 20974691 in words is "twenty million, nine hundred seventy-four thousand, six hundred ninety-one".