20690975 has 6 divisors (see below), whose sum is σ = 25656840. Its totient is φ = 16552760.

The previous prime is 20690939. The next prime is 20690977. The reversal of 20690975 is 57909602.

It is not a de Polignac number, because 20690975 - 2¹² = 20686879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20690977) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 413795 + ... + 413844.

It is an arithmetic number, because the mean of its divisors is an integer number (4276140).

Almost surely, 2^20690975 is an apocalyptic number.

20690975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20690975 is a deficient number, since it is larger than the sum of its proper divisors (4965865).

20690975 is an equidigital number, since it uses as much as digits as its factorization.

20690975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 827649 (or 827644 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 20690975 is about 4548.7333401728. The cubic root of 20690975 is about 274.5324285983.

The spelling of 20690975 in words is "twenty million, six hundred ninety thousand, nine hundred seventy-five".