20947870 has 8 divisors (see below), whose sum is σ = 37706184. Its totient is φ = 8379144.

The previous prime is 20947867. The next prime is 20947873. The reversal of 20947870 is 7874902.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20947867) and next prime (20947873).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20947873) 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, 1047384 + ... + 1047403.

It is an arithmetic number, because the mean of its divisors is an integer number (4713273).

Almost surely, 2^20947870 is an apocalyptic number.

20947870 is a deficient number, since it is larger than the sum of its proper divisors (16758314).

20947870 is a wasteful number, since it uses less digits than its factorization.

20947870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2094794.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 20947870 is about 4576.8843114066. The cubic root of 20947870 is about 275.6639384487.

The spelling of 20947870 in words is "twenty million, nine hundred forty-seven thousand, eight hundred seventy".