21734157 has 8 divisors (see below), whose sum is σ = 30504160. Its totient is φ = 13726800.

The previous prime is 21734147. The next prime is 21734171. The reversal of 21734157 is 75143712.

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

It is not a de Polignac number, because 21734157 - 2⁷ = 21734029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21734147) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 190594 + ... + 190707.

It is an arithmetic number, because the mean of its divisors is an integer number (3813020).

Almost surely, 2^21734157 is an apocalyptic number.

It is an amenable number.

21734157 is a deficient number, since it is larger than the sum of its proper divisors (8770003).

21734157 is a wasteful number, since it uses less digits than its factorization.

21734157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381323.

The product of its digits is 5880, while the sum is 30.

The square root of 21734157 is about 4661.9906692313. The cubic root of 21734157 is about 279.0707160066.

Adding to 21734157 its reverse (75143712), we get a palindrome (96877869).

The spelling of 21734157 in words is "twenty-one million, seven hundred thirty-four thousand, one hundred fifty-seven".