20742955 has 4 divisors (see below), whose sum is σ = 24891552. Its totient is φ = 16594360.

The previous prime is 20742949. The next prime is 20742961. The reversal of 20742955 is 55924702.

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

It is an interprime number because it is at equal distance from previous prime (20742949) and next prime (20742961).

It is not a de Polignac number, because 20742955 - 2⁹ = 20742443 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20742955.

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, 2074291 + ... + 2074300.

It is an arithmetic number, because the mean of its divisors is an integer number (6222888).

Almost surely, 2^20742955 is an apocalyptic number.

20742955 is a deficient number, since it is larger than the sum of its proper divisors (4148597).

20742955 is an equidigital number, since it uses as much as digits as its factorization.

20742955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4148596.

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 20742955 is about 4554.4434347130. The cubic root of 20742955 is about 274.7621303949.

The spelling of 20742955 in words is "twenty million, seven hundred forty-two thousand, nine hundred fifty-five".