21157346 has 8 divisors (see below), whose sum is σ = 36269760. Its totient is φ = 9067428.

The previous prime is 21157343. The next prime is 21157351. The reversal of 21157346 is 64375112.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21157343) 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, 755606 + ... + 755633.

It is an arithmetic number, because the mean of its divisors is an integer number (4533720).

Almost surely, 2^21157346 is an apocalyptic number.

21157346 is a deficient number, since it is larger than the sum of its proper divisors (15112414).

21157346 is a wasteful number, since it uses less digits than its factorization.

21157346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1511248.

The product of its digits is 5040, while the sum is 29.

The square root of 21157346 is about 4599.7115126929. The cubic root of 21157346 is about 276.5797604493.

The spelling of 21157346 in words is "twenty-one million, one hundred fifty-seven thousand, three hundred forty-six".