21770532 has 120 divisors (see below), whose sum is σ = 67488960. Its totient is φ = 5987520.

The previous prime is 21770531. The next prime is 21770543. The reversal of 21770532 is 23507712.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21770496 and 21770505.

It is not an unprimeable number, because it can be changed into a prime (21770531) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 65607 + ... + 65937.

It is an arithmetic number, because the mean of its divisors is an integer number (562408).

Almost surely, 2^21770532 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21770532, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33744480).

21770532 is an abundant number, since it is smaller than the sum of its proper divisors (45718428).

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

21770532 is a wasteful number, since it uses less digits than its factorization.

21770532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383 (or 372 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 21770532 is about 4665.8902687483. The cubic root of 21770532 is about 279.2263165425.

The spelling of 21770532 in words is "twenty-one million, seven hundred seventy thousand, five hundred thirty-two".