20897830 has 16 divisors (see below), whose sum is σ = 37680624. Its totient is φ = 8344800.

The previous prime is 20897827. The next prime is 20897839. The reversal of 20897830 is 3879802.

It is a self number, because there is not a number n which added to its sum of digits gives 20897830.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20897839) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5905 + ... + 8755.

It is an arithmetic number, because the mean of its divisors is an integer number (2355039).

Almost surely, 2^20897830 is an apocalyptic number.

20897830 is a deficient number, since it is larger than the sum of its proper divisors (16782794).

20897830 is a wasteful number, since it uses less digits than its factorization.

20897830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3591.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 20897830 is about 4571.4144419424. The cubic root of 20897830 is about 275.4442626233. Note that the first 3 decimals are identical.

The spelling of 20897830 in words is "twenty million, eight hundred ninety-seven thousand, eight hundred thirty".