20645677 has 8 divisors (see below), whose sum is σ = 22269464. Its totient is φ = 19027008.

The previous prime is 20645671. The next prime is 20645683. The reversal of 20645677 is 77654602.

It is an interprime number because it is at equal distance from previous prime (20645671) and next prime (20645683).

It can be written as a sum of positive squares in 4 ways, for example, as 11519236 + 9126441 = 3394^2 + 3021^2 .

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

It is not a de Polignac number, because 20645677 - 2¹⁵ = 20612909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20645671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13483 + ... + 14935.

It is an arithmetic number, because the mean of its divisors is an integer number (2783683).

Almost surely, 2^20645677 is an apocalyptic number.

It is an amenable number.

20645677 is a deficient number, since it is larger than the sum of its proper divisors (1623787).

20645677 is a wasteful number, since it uses less digits than its factorization.

20645677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2559.

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

The square root of 20645677 is about 4543.7514236586. The cubic root of 20645677 is about 274.3319409289.

The spelling of 20645677 in words is "twenty million, six hundred forty-five thousand, six hundred seventy-seven".