21254357 has 8 divisors (see below), whose sum is σ = 21669120. Its totient is φ = 20843680.

The previous prime is 21254329. The next prime is 21254371. The reversal of 21254357 is 75345212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21254357 - 2¹⁰ = 21253333 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 (21254327) 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, 10748 + ... + 12570.

It is an arithmetic number, because the mean of its divisors is an integer number (2708640).

Almost surely, 2^21254357 is an apocalyptic number.

It is an amenable number.

21254357 is a deficient number, since it is larger than the sum of its proper divisors (414763).

21254357 is a wasteful number, since it uses less digits than its factorization.

21254357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2043.

The product of its digits is 8400, while the sum is 29.

The square root of 21254357 is about 4610.2447874272. The cubic root of 21254357 is about 277.0018419684.

Adding to 21254357 its reverse (75345212), we get a palindrome (96599569).

The spelling of 21254357 in words is "twenty-one million, two hundred fifty-four thousand, three hundred fifty-seven".