20947490 has 8 divisors (see below), whose sum is σ = 37705500. Its totient is φ = 8378992.

The previous prime is 20947471. The next prime is 20947499. The reversal of 20947490 is 9474902.

It can be written as a sum of positive squares in 2 ways, for example, as 19509889 + 1437601 = 4417^2 + 1199^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20947490.

It is not an unprimeable number, because it can be changed into a prime (20947499) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1047365 + ... + 1047384.

Almost surely, 2^20947490 is an apocalyptic number.

20947490 is a deficient number, since it is larger than the sum of its proper divisors (16758010).

20947490 is a wasteful number, since it uses less digits than its factorization.

20947490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2094756.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 20947490 is about 4576.8427982617. The cubic root of 20947490 is about 275.6622715660.

The spelling of 20947490 in words is "twenty million, nine hundred forty-seven thousand, four hundred ninety".