20742665 has 8 divisors (see below), whose sum is σ = 25973568. Its totient is φ = 15872560.

The previous prime is 20742653. The next prime is 20742677. The reversal of 20742665 is 56624702.

It is an interprime number because it is at equal distance from previous prime (20742653) and next prime (20742677).

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

It is not a de Polignac number, because 20742665 - 2⁴ = 20742649 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90071 + ... + 90300.

It is an arithmetic number, because the mean of its divisors is an integer number (3246696).

Almost surely, 2^20742665 is an apocalyptic number.

It is an amenable number.

20742665 is a deficient number, since it is larger than the sum of its proper divisors (5230903).

20742665 is a wasteful number, since it uses less digits than its factorization.

20742665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180399.

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 20742665 is about 4554.4115975612. The cubic root of 20742665 is about 274.7608499379.

The spelling of 20742665 in words is "twenty million, seven hundred forty-two thousand, six hundred sixty-five".