20156742 has 16 divisors (see below), whose sum is σ = 44792880. Its totient is φ = 6718896.

The previous prime is 20156737. The next prime is 20156753. The reversal of 20156742 is 24765102.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 186583 + ... + 186690.

It is an arithmetic number, because the mean of its divisors is an integer number (2799555).

Almost surely, 2^20156742 is an apocalyptic number.

20156742 is an abundant number, since it is smaller than the sum of its proper divisors (24636138).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20156742 is a wasteful number, since it uses less digits than its factorization.

20156742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373284 (or 373278 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 20156742 is about 4489.6260423336. The cubic root of 20156742 is about 272.1490226498.

The spelling of 20156742 in words is "twenty million, one hundred fifty-six thousand, seven hundred forty-two".