20861010 has 32 divisors (see below), whose sum is σ = 55630080. Its totient is φ = 5562864.

The previous prime is 20860969. The next prime is 20861017. The reversal of 20861010 is 1016802.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20861017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38362 + ... + 38901.

It is an arithmetic number, because the mean of its divisors is an integer number (1738440).

Almost surely, 2^20861010 is an apocalyptic number.

20861010 is an abundant number, since it is smaller than the sum of its proper divisors (34769070).

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

20861010 is a wasteful number, since it uses less digits than its factorization.

20861010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77279 (or 77273 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 20861010 is about 4567.3854665443. The cubic root of 20861010 is about 275.2823986097.

Adding to 20861010 its reverse (1016802), we get a palindrome (21877812).

The spelling of 20861010 in words is "twenty million, eight hundred sixty-one thousand, ten".