21121276 has 54 divisors (see below), whose sum is σ = 43444184. Its totient is φ = 8976000.

The previous prime is 21121271. The next prime is 21121277. The reversal of 21121276 is 67212112.

It is a happy number.

It is a super-2 number, since 2×21121276² = 892216599736352, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 139801 + ... + 139951.

Almost surely, 2^21121276 is an apocalyptic number.

It is an amenable number.

21121276 is an abundant number, since it is smaller than the sum of its proper divisors (22322908).

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

21121276 is a wasteful number, since it uses less digits than its factorization.

21121276 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211 (or 181 counting only the distinct ones).

The product of its digits is 336, while the sum is 22.

The square root of 21121276 is about 4595.7889420642. The cubic root of 21121276 is about 276.4224958182.

Adding to 21121276 its reverse (67212112), we get a palindrome (88333388).

The spelling of 21121276 in words is "twenty-one million, one hundred twenty-one thousand, two hundred seventy-six".