21770694 has 80 divisors (see below), whose sum is σ = 56105280. Its totient is φ = 6240240.

The previous prime is 21770687. The next prime is 21770701. The reversal of 21770694 is 49607712.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21770687) and next prime (21770701).

It is a congruent number.

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 33537 + ... + 34179.

It is an arithmetic number, because the mean of its divisors is an integer number (701316).

Almost surely, 2^21770694 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21770694, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28052640).

21770694 is an abundant number, since it is smaller than the sum of its proper divisors (34334586).

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

21770694 is a wasteful number, since it uses less digits than its factorization.

21770694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687 (or 678 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 21770694 is about 4665.9076287471. The cubic root of 21770694 is about 279.2270091385.

The spelling of 21770694 in words is "twenty-one million, seven hundred seventy thousand, six hundred ninety-four".