20765690 has 16 divisors (see below), whose sum is σ = 40776480. Its totient is φ = 7551120.

The previous prime is 20765669. The next prime is 20765707. The reversal of 20765690 is 9656702.

It is a super-2 number, since 2×20765690² = 862427762352200, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20765690.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94280 + ... + 94499.

It is an arithmetic number, because the mean of its divisors is an integer number (2548530).

Almost surely, 2^20765690 is an apocalyptic number.

20765690 is a deficient number, since it is larger than the sum of its proper divisors (20010790).

20765690 is a wasteful number, since it uses less digits than its factorization.

20765690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188797.

The product of its (nonzero) digits is 22680, while the sum is 35.

The square root of 20765690 is about 4556.9386653761. The cubic root of 20765690 is about 274.8624766927.

The spelling of 20765690 in words is "twenty million, seven hundred sixty-five thousand, six hundred ninety".