20690867 has 4 divisors (see below), whose sum is σ = 21779880. Its totient is φ = 19601856.

The previous prime is 20690849. The next prime is 20690897. The reversal of 20690867 is 76809602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76809602 = 2 ⋅38404801.

It is a cyclic number.

It is not a de Polignac number, because 20690867 - 2²⁰ = 19642291 is a prime.

It is a super-2 number, since 2×20690867² = 856223954423378, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20690867.

It is not an unprimeable number, because it can be changed into a prime (20690827) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 544478 + ... + 544515.

It is an arithmetic number, because the mean of its divisors is an integer number (5444970).

Almost surely, 2^20690867 is an apocalyptic number.

20690867 is a deficient number, since it is larger than the sum of its proper divisors (1089013).

20690867 is a wasteful number, since it uses less digits than its factorization.

20690867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1089012.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 20690867 is about 4548.7214687206. The cubic root of 20690867 is about 274.5319509415.

The spelling of 20690867 in words is "twenty million, six hundred ninety thousand, eight hundred sixty-seven".