21512122 has 8 divisors (see below), whose sum is σ = 32288256. Its totient is φ = 10749372.

The previous prime is 21512093. The next prime is 21512129. The reversal of 21512122 is 22121512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21512096 and 21512105.

It is not an unprimeable number, because it can be changed into a prime (21512129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3373 + ... + 7375.

It is an arithmetic number, because the mean of its divisors is an integer number (4036032).

Almost surely, 2^21512122 is an apocalyptic number.

21512122 is a deficient number, since it is larger than the sum of its proper divisors (10776134).

21512122 is a wasteful number, since it uses less digits than its factorization.

21512122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6692.

The product of its digits is 80, while the sum is 16.

The square root of 21512122 is about 4638.1162124294. The cubic root of 21512122 is about 278.1171374624.

Adding to 21512122 its reverse (22121512), we get a palindrome (43633634).

The spelling of 21512122 in words is "twenty-one million, five hundred twelve thousand, one hundred twenty-two".