20806502 has 4 divisors (see below), whose sum is σ = 31209756. Its totient is φ = 10403250.

The previous prime is 20806459. The next prime is 20806507. The reversal of 20806502 is 20560802.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20806507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5201624 + ... + 5201627.

It is an arithmetic number, because the mean of its divisors is an integer number (7802439).

Almost surely, 2^20806502 is an apocalyptic number.

20806502 is a deficient number, since it is larger than the sum of its proper divisors (10403254).

20806502 is a wasteful number, since it uses less digits than its factorization.

20806502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10403253.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 20806502 is about 4561.4144736036. The cubic root of 20806502 is about 275.0424265120.

The spelling of 20806502 in words is "twenty million, eight hundred six thousand, five hundred two".