21770086 has 32 divisors (see below), whose sum is σ = 37416960. Its totient is φ = 9416736.

The previous prime is 21770059. The next prime is 21770087. The reversal of 21770086 is 68007712.

It is a happy number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21770087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62565 + ... + 62911.

It is an arithmetic number, because the mean of its divisors is an integer number (1169280).

Almost surely, 2^21770086 is an apocalyptic number.

21770086 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21770086 is a deficient number, since it is larger than the sum of its proper divisors (15646874).

21770086 is a wasteful number, since it uses less digits than its factorization.

21770086 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508.

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 21770086 is about 4665.8424748377. The cubic root of 21770086 is about 279.2244097481.

Adding to 21770086 its reverse (68007712), we get a palindrome (89777798).

The spelling of 21770086 in words is "twenty-one million, seven hundred seventy thousand, eighty-six".