21715086 has 32 divisors (see below), whose sum is σ = 47063808. Its totient is φ = 6652800.

The previous prime is 21715063. The next prime is 21715087. The reversal of 21715086 is 68051712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21715087) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1911 + ... + 6861.

It is an arithmetic number, because the mean of its divisors is an integer number (1470744).

Almost surely, 2^21715086 is an apocalyptic number.

21715086 is an abundant number, since it is smaller than the sum of its proper divisors (25348722).

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

21715086 is a wasteful number, since it uses less digits than its factorization.

21715086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5016.

The product of its (nonzero) digits is 3360, while the sum is 30.

The square root of 21715086 is about 4659.9448494591. The cubic root of 21715086 is about 278.9890670296.

Adding to 21715086 its reverse (68051712), we get a palindrome (89766798).

The spelling of 21715086 in words is "twenty-one million, seven hundred fifteen thousand, eighty-six".