20690745 has 8 divisors (see below), whose sum is σ = 33105216. Its totient is φ = 11035056.

The previous prime is 20690737. The next prime is 20690767. The reversal of 20690745 is 54709602.

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

It is not a de Polignac number, because 20690745 - 2³ = 20690737 is a prime.

It is a Curzon 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, 689677 + ... + 689706.

It is an arithmetic number, because the mean of its divisors is an integer number (4138152).

Almost surely, 2^20690745 is an apocalyptic number.

It is an amenable number.

20690745 is a deficient number, since it is larger than the sum of its proper divisors (12414471).

20690745 is a wasteful number, since it uses less digits than its factorization.

20690745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1379391.

The product of its (nonzero) digits is 15120, while the sum is 33.

The square root of 20690745 is about 4548.7080583392. The cubic root of 20690745 is about 274.5314113642.

It can be divided in two parts, 206 and 90745, that added together give a triangular number (90951 = T₄₂₆).

The spelling of 20690745 in words is "twenty million, six hundred ninety thousand, seven hundred forty-five".