20742493 has 2 divisors, whose sum is σ = 20742494. Its totient is φ = 20742492.

The previous prime is 20742487. The next prime is 20742517. The reversal of 20742493 is 39424702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18992164 + 1750329 = 4358^2 + 1323^2 .

It is a cyclic number.

It is not a de Polignac number, because 20742493 - 2⁵ = 20742461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20742413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10371246 + 10371247.

It is an arithmetic number, because the mean of its divisors is an integer number (10371247).

Almost surely, 2^20742493 is an apocalyptic number.

It is an amenable number.

20742493 is a deficient number, since it is larger than the sum of its proper divisors (1).

20742493 is an equidigital number, since it uses as much as digits as its factorization.

20742493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 31.

The square root of 20742493 is about 4554.3927147316. The cubic root of 20742493 is about 274.7600904888.

The spelling of 20742493 in words is "twenty million, seven hundred forty-two thousand, four hundred ninety-three".