21770436 has 24 divisors (see below), whose sum is σ = 50874880. Its totient is φ = 7245792.

The previous prime is 21770431. The next prime is 21770453. The reversal of 21770436 is 63407712.

It is not an unprimeable number, because it can be changed into a prime (21770431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12210 + ... + 13878.

Almost surely, 2^21770436 is an apocalyptic number.

It is an amenable number.

21770436 is an abundant number, since it is smaller than the sum of its proper divisors (29104444).

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

21770436 is a wasteful number, since it uses less digits than its factorization.

21770436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2763 (or 2761 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 30.

The square root of 21770436 is about 4665.8799813111. The cubic root of 21770436 is about 279.2259061136.

The spelling of 21770436 in words is "twenty-one million, seven hundred seventy thousand, four hundred thirty-six".