21180722 has 4 divisors (see below), whose sum is σ = 31771086. Its totient is φ = 10590360.

The previous prime is 21180707. The next prime is 21180727. The reversal of 21180722 is 22708112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21058921 + 121801 = 4589^2 + 349^2 .

It is not an unprimeable number, because it can be changed into a prime (21180727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5295179 + ... + 5295182.

Almost surely, 2^21180722 is an apocalyptic number.

21180722 is a deficient number, since it is larger than the sum of its proper divisors (10590364).

21180722 is a wasteful number, since it uses less digits than its factorization.

21180722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10590363.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 21180722 is about 4602.2518401322. The cubic root of 21180722 is about 276.6815840088.

Adding to 21180722 its reverse (22708112), we get a palindrome (43888834).

The spelling of 21180722 in words is "twenty-one million, one hundred eighty thousand, seven hundred twenty-two".