21172022 has 4 divisors (see below), whose sum is σ = 31758036. Its totient is φ = 10586010.

The previous prime is 21172009. The next prime is 21172037. The reversal of 21172022 is 22027112.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5293004 + ... + 5293007.

It is an arithmetic number, because the mean of its divisors is an integer number (7939509).

Almost surely, 2^21172022 is an apocalyptic number.

21172022 is a deficient number, since it is larger than the sum of its proper divisors (10586014).

21172022 is a wasteful number, since it uses less digits than its factorization.

21172022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10586013.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 21172022 is about 4601.3065535780. The cubic root of 21172022 is about 276.6436964204.

Adding to 21172022 its reverse (22027112), we get a palindrome (43199134).

The spelling of 21172022 in words is "twenty-one million, one hundred seventy-two thousand, twenty-two".