21211148 has 24 divisors (see below), whose sum is σ = 42938112. Its totient is φ = 8979984.

The previous prime is 21211139. The next prime is 21211181. The reversal of 21211148 is 84111212.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2240 + ... + 6887.

It is an arithmetic number, because the mean of its divisors is an integer number (1789088).

Almost surely, 2^21211148 is an apocalyptic number.

21211148 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21211148 is an abundant number, since it is smaller than the sum of its proper divisors (21726964).

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

21211148 is a wasteful number, since it uses less digits than its factorization.

21211148 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9221 (or 9219 counting only the distinct ones).

The product of its digits is 128, while the sum is 20.

The square root of 21211148 is about 4605.5562096233. The cubic root of 21211148 is about 276.8140045205.

It can be divided in two parts, 212111 and 48, that multiplied together give a triangular number (10181328 = T₄₅₁₂).

The spelling of 21211148 in words is "twenty-one million, two hundred eleven thousand, one hundred forty-eight".