20490278 has 4 divisors (see below), whose sum is σ = 30735420. Its totient is φ = 10245138.

The previous prime is 20490271. The next prime is 20490299. The reversal of 20490278 is 87209402.

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 (20490271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5122568 + ... + 5122571.

It is an arithmetic number, because the mean of its divisors is an integer number (7683855).

Almost surely, 2^20490278 is an apocalyptic number.

20490278 is a deficient number, since it is larger than the sum of its proper divisors (10245142).

20490278 is a wasteful number, since it uses less digits than its factorization.

20490278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10245141.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 20490278 is about 4526.6188264531. The cubic root of 20490278 is about 273.6419123890.

The spelling of 20490278 in words is "twenty million, four hundred ninety thousand, two hundred seventy-eight".