21778962 has 16 divisors (see below), whose sum is σ = 43691232. Its totient is φ = 7237440.

The previous prime is 21778949. The next prime is 21778969. The reversal of 21778962 is 26987712.

It is not an unprimeable number, because it can be changed into a prime (21778969) 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, 3364 + ... + 7407.

It is an arithmetic number, because the mean of its divisors is an integer number (2730702).

Almost surely, 2^21778962 is an apocalyptic number.

21778962 is an abundant number, since it is smaller than the sum of its proper divisors (21912270).

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

21778962 is a wasteful number, since it uses less digits than its factorization.

21778962 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11113.

The product of its digits is 84672, while the sum is 42.

The square root of 21778962 is about 4666.7935458942. The cubic root of 21778962 is about 279.2623526255.

The spelling of 21778962 in words is "twenty-one million, seven hundred seventy-eight thousand, nine hundred sixty-two".