20861087 has 8 divisors (see below), whose sum is σ = 23014320. Its totient is φ = 18786240.

The previous prime is 20861083. The next prime is 20861089. The reversal of 20861087 is 78016802.

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 20861087 - 2² = 20861083 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20861083) 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, 19037 + ... + 20102.

It is an arithmetic number, because the mean of its divisors is an integer number (2876790).

Almost surely, 2^20861087 is an apocalyptic number.

20861087 is a deficient number, since it is larger than the sum of its proper divisors (2153233).

20861087 is a wasteful number, since it uses less digits than its factorization.

20861087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39193.

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

The square root of 20861087 is about 4567.3938958667. The cubic root of 20861087 is about 275.2827373072.

Adding to 20861087 its reverse (78016802), we get a palindrome (98877889).

The spelling of 20861087 in words is "twenty million, eight hundred sixty-one thousand, eighty-seven".