21231152 has 10 divisors (see below), whose sum is σ = 41135388. Its totient is φ = 10615568.

The previous prime is 21231143. The next prime is 21231173. The reversal of 21231152 is 25113212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21231152.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 663458 + ... + 663489.

Almost surely, 2^21231152 is an apocalyptic number.

It is an amenable number.

21231152 is a deficient number, since it is larger than the sum of its proper divisors (19904236).

21231152 is a wasteful number, since it uses less digits than its factorization.

21231152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1326955 (or 1326949 counting only the distinct ones).

The product of its digits is 120, while the sum is 17.

The square root of 21231152 is about 4607.7274224937. The cubic root of 21231152 is about 276.9009972583.

Adding to 21231152 its reverse (25113212), we get a palindrome (46344364).

The spelling of 21231152 in words is "twenty-one million, two hundred thirty-one thousand, one hundred fifty-two".