20847290 has 16 divisors (see below), whose sum is σ = 37801512. Its totient is φ = 8277504.

The previous prime is 20847289. The next prime is 20847293. The reversal of 20847290 is 9274802.

It can be written as a sum of positive squares in 4 ways, for example, as 19829209 + 1018081 = 4453^2 + 1009^2 .

It is not an unprimeable number, because it can be changed into a prime (20847293) 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, 6239 + ... + 8978.

Almost surely, 2^20847290 is an apocalyptic number.

20847290 is a deficient number, since it is larger than the sum of its proper divisors (16954222).

20847290 is a wasteful number, since it uses less digits than its factorization.

20847290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15361.

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

The square root of 20847290 is about 4565.8832661381. The cubic root of 20847290 is about 275.2220355558. Note that the first 3 decimals are identical.

The spelling of 20847290 in words is "twenty million, eight hundred forty-seven thousand, two hundred ninety".