20666670 has 16 divisors (see below), whose sum is σ = 49600080. Its totient is φ = 5511104.

The previous prime is 20666669. The next prime is 20666671. The reversal of 20666670 is 7666602.

It is an interprime number because it is at equal distance from previous prime (20666669) and next prime (20666671).

It is a super-2 number, since 2×20666670² = 854222497777800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666671) 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, 344415 + ... + 344474.

It is an arithmetic number, because the mean of its divisors is an integer number (3100005).

Almost surely, 2^20666670 is an apocalyptic number.

20666670 is an abundant number, since it is smaller than the sum of its proper divisors (28933410).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20666670 is a wasteful number, since it uses less digits than its factorization.

20666670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688899.

The product of its (nonzero) digits is 18144, while the sum is 33.

The square root of 20666670 is about 4546.0609322797. The cubic root of 20666670 is about 274.4248917770.

The spelling of 20666670 in words is "twenty million, six hundred sixty-six thousand, six hundred seventy".