20842351 has 4 divisors (see below), whose sum is σ = 21006592. Its totient is φ = 20678112.

The previous prime is 20842343. The next prime is 20842361. The reversal of 20842351 is 15324802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15324802 = 2 ⋅7662401.

It is a cyclic number.

It is not a de Polignac number, because 20842351 - 2³ = 20842343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20842361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81930 + ... + 82183.

It is an arithmetic number, because the mean of its divisors is an integer number (5251648).

Almost surely, 2^20842351 is an apocalyptic number.

20842351 is a deficient number, since it is larger than the sum of its proper divisors (164241).

20842351 is a wasteful number, since it uses less digits than its factorization.

20842351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164240.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 20842351 is about 4565.3423748937. The cubic root of 20842351 is about 275.2002992535.

The spelling of 20842351 in words is "twenty million, eight hundred forty-two thousand, three hundred fifty-one".