20870861 has 8 divisors (see below), whose sum is σ = 22828800. Its totient is φ = 18923040.

The previous prime is 20870813. The next prime is 20870869. The reversal of 20870861 is 16807802.

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

It is a cyclic number.

It is not a de Polignac number, because 20870861 - 2¹⁰ = 20869837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20870869) 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, 2180 + ... + 6818.

It is an arithmetic number, because the mean of its divisors is an integer number (2853600).

Almost surely, 2^20870861 is an apocalyptic number.

It is an amenable number.

20870861 is a deficient number, since it is larger than the sum of its proper divisors (1957939).

20870861 is a wasteful number, since it uses less digits than its factorization.

20870861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5059.

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 20870861 is about 4568.4637461624. The cubic root of 20870861 is about 275.3257231365.

The spelling of 20870861 in words is "twenty million, eight hundred seventy thousand, eight hundred sixty-one".