20493218 has 4 divisors (see below), whose sum is σ = 30739830. Its totient is φ = 10246608.

The previous prime is 20493197. The next prime is 20493257. The reversal of 20493218 is 81239402.

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

It can be written as a sum of positive squares in only one way, i.e., 19775809 + 717409 = 4447^2 + 847^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5123303 + ... + 5123306.

Almost surely, 2^20493218 is an apocalyptic number.

20493218 is a deficient number, since it is larger than the sum of its proper divisors (10246612).

20493218 is a wasteful number, since it uses less digits than its factorization.

20493218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10246611.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 20493218 is about 4526.9435605053. The cubic root of 20493218 is about 273.6549993880.

The spelling of 20493218 in words is "twenty million, four hundred ninety-three thousand, two hundred eighteen".