20897144 has 8 divisors (see below), whose sum is σ = 39182160. Its totient is φ = 10448568.

The previous prime is 20897143. The next prime is 20897147. The reversal of 20897144 is 44179802.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20897143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1306064 + ... + 1306079.

It is an arithmetic number, because the mean of its divisors is an integer number (4897770).

Almost surely, 2^20897144 is an apocalyptic number.

It is an amenable number.

20897144 is a deficient number, since it is larger than the sum of its proper divisors (18285016).

20897144 is a wasteful number, since it uses less digits than its factorization.

20897144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2612149 (or 2612145 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 20897144 is about 4571.3394098448. The cubic root of 20897144 is about 275.4412486448.

The spelling of 20897144 in words is "twenty million, eight hundred ninety-seven thousand, one hundred forty-four".