20645697 has 8 divisors (see below), whose sum is σ = 28724544. Its totient is φ = 13165328.

The previous prime is 20645683. The next prime is 20645707. The reversal of 20645697 is 79654602.

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

It is a cyclic number.

It is not a de Polignac number, because 20645697 - 2⁸ = 20645441 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20645197) 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 7 ways as a sum of consecutive naturals, for example, 149538 + ... + 149675.

It is an arithmetic number, because the mean of its divisors is an integer number (3590568).

Almost surely, 2^20645697 is an apocalyptic number.

It is an amenable number.

20645697 is a deficient number, since it is larger than the sum of its proper divisors (8078847).

20645697 is a wasteful number, since it uses less digits than its factorization.

20645697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299239.

The product of its (nonzero) digits is 90720, while the sum is 39.

The square root of 20645697 is about 4543.7536244827. The cubic root of 20645697 is about 274.3320295130.

The spelling of 20645697 in words is "twenty million, six hundred forty-five thousand, six hundred ninety-seven".