20742842 has 4 divisors (see below), whose sum is σ = 31114266. Its totient is φ = 10371420.

The previous prime is 20742833. The next prime is 20742857. The reversal of 20742842 is 24824702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18757561 + 1985281 = 4331^2 + 1409^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5185709 + ... + 5185712.

Almost surely, 2^20742842 is an apocalyptic number.

20742842 is a deficient number, since it is larger than the sum of its proper divisors (10371424).

20742842 is a wasteful number, since it uses less digits than its factorization.

20742842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10371423.

The product of its (nonzero) digits is 7168, while the sum is 29.

The square root of 20742842 is about 4554.4310292286. The cubic root of 20742842 is about 274.7616314596.

The spelling of 20742842 in words is "twenty million, seven hundred forty-two thousand, eight hundred forty-two".