20746657 has 4 divisors (see below), whose sum is σ = 21415936. Its totient is φ = 20077380.

The previous prime is 20746639. The next prime is 20746709. The reversal of 20746657 is 75664702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75664702 = 2 ⋅37832351.

It is a cyclic number.

It is not a de Polignac number, because 20746657 - 2¹¹ = 20744609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20246657) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 334593 + ... + 334654.

It is an arithmetic number, because the mean of its divisors is an integer number (5353984).

Almost surely, 2^20746657 is an apocalyptic number.

It is an amenable number.

20746657 is a deficient number, since it is larger than the sum of its proper divisors (669279).

20746657 is an equidigital number, since it uses as much as digits as its factorization.

20746657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 669278.

The product of its (nonzero) digits is 70560, while the sum is 37.

The square root of 20746657 is about 4554.8498328705. The cubic root of 20746657 is about 274.7784750431.

It can be divided in two parts, 207 and 46657, that added together give a palindrome (46864).

The spelling of 20746657 in words is "twenty million, seven hundred forty-six thousand, six hundred fifty-seven".