20690545 has 8 divisors (see below), whose sum is σ = 24877800. Its totient is φ = 16519680.

The previous prime is 20690539. The next prime is 20690591. The reversal of 20690545 is 54509602.

It can be written as a sum of positive squares in 4 ways, for example, as 6241 + 20684304 = 79^2 + 4548^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-20690545 is a prime.

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, 1120 + ... + 6529.

It is an arithmetic number, because the mean of its divisors is an integer number (3109725).

Almost surely, 2^20690545 is an apocalyptic number.

It is an amenable number.

20690545 is a deficient number, since it is larger than the sum of its proper divisors (4187255).

20690545 is an equidigital number, since it uses as much as digits as its factorization.

20690545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8195.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 20690545 is about 4548.6860740218. The cubic root of 20690545 is about 274.5305268068.

The spelling of 20690545 in words is "twenty million, six hundred ninety thousand, five hundred forty-five".