21233157 has 8 divisors (see below), whose sum is σ = 30884640. Its totient is φ = 12868560.

The previous prime is 21233131. The next prime is 21233161. The reversal of 21233157 is 75133212.

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

It is not a de Polignac number, because 21233157 - 2⁷ = 21233029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21233197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 321682 + ... + 321747.

It is an arithmetic number, because the mean of its divisors is an integer number (3860580).

Almost surely, 2^21233157 is an apocalyptic number.

It is an amenable number.

21233157 is a deficient number, since it is larger than the sum of its proper divisors (9651483).

21233157 is a wasteful number, since it uses less digits than its factorization.

21233157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643443.

The product of its digits is 1260, while the sum is 24.

The square root of 21233157 is about 4607.9449866508. The cubic root of 21233157 is about 276.9097135230.

Adding to 21233157 its reverse (75133212), we get a palindrome (96366369).

The spelling of 21233157 in words is "twenty-one million, two hundred thirty-three thousand, one hundred fifty-seven".