21774312 has 64 divisors (see below), whose sum is σ = 69129600. Its totient is φ = 6220800.

The previous prime is 21774289. The next prime is 21774317. The reversal of 21774312 is 21347712.

It is a happy number.

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

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21774317) 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, 5689 + ... + 8712.

It is an arithmetic number, because the mean of its divisors is an integer number (1080150).

Almost surely, 2^21774312 is an apocalyptic number.

It is an amenable number.

21774312 is an abundant number, since it is smaller than the sum of its proper divisors (47355288).

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

21774312 is a wasteful number, since it uses less digits than its factorization.

21774312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14423 (or 14413 counting only the distinct ones).

The product of its digits is 2352, while the sum is 27.

The square root of 21774312 is about 4666.2953185584. The cubic root of 21774312 is about 279.2424762210.

It can be divided in two parts, 217 and 74312, that added together give a square (74529 = 273²).

The spelling of 21774312 in words is "twenty-one million, seven hundred seventy-four thousand, three hundred twelve".