20742479 has 2 divisors, whose sum is σ = 20742480. Its totient is φ = 20742478.

The previous prime is 20742461. The next prime is 20742487. The reversal of 20742479 is 97424702.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20742479 - 2⁸ = 20742223 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20742179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10371239 + 10371240.

It is an arithmetic number, because the mean of its divisors is an integer number (10371240).

Almost surely, 2^20742479 is an apocalyptic number.

20742479 is a deficient number, since it is larger than the sum of its proper divisors (1).

20742479 is an equidigital number, since it uses as much as digits as its factorization.

20742479 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 35.

The square root of 20742479 is about 4554.3911777536. The cubic root of 20742479 is about 274.7600286729.

The spelling of 20742479 in words is "twenty million, seven hundred forty-two thousand, four hundred seventy-nine".