21778362 has 32 divisors (see below), whose sum is σ = 50068800. Its totient is φ = 7008624.

The previous prime is 21778349. The next prime is 21778369. The reversal of 21778362 is 26387712.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (21778369) 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, 5388 + ... + 8519.

It is an arithmetic number, because the mean of its divisors is an integer number (1564650).

Almost surely, 2^21778362 is an apocalyptic number.

21778362 is an abundant number, since it is smaller than the sum of its proper divisors (28290438).

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

21778362 is a wasteful number, since it uses less digits than its factorization.

21778362 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13947 (or 13941 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The square root of 21778362 is about 4666.7292614850. The cubic root of 21778362 is about 279.2597880871.

The spelling of 21778362 in words is "twenty-one million, seven hundred seventy-eight thousand, three hundred sixty-two".