20428742 has 8 divisors (see below), whose sum is σ = 31390632. Its totient is φ = 9965200.

The previous prime is 20428739. The next prime is 20428757. The reversal of 20428742 is 24782402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124484 + ... + 124647.

It is an arithmetic number, because the mean of its divisors is an integer number (3923829).

Almost surely, 2^20428742 is an apocalyptic number.

20428742 is a deficient number, since it is larger than the sum of its proper divisors (10961890).

20428742 is a wasteful number, since it uses less digits than its factorization.

20428742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249174.

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

The square root of 20428742 is about 4519.8165891992. The cubic root of 20428742 is about 273.3677057045.

The spelling of 20428742 in words is "twenty million, four hundred twenty-eight thousand, seven hundred forty-two".