21890357 has 8 divisors (see below), whose sum is σ = 22351680. Its totient is φ = 21432160.

The previous prime is 21890329. The next prime is 21890369. The reversal of 21890357 is 75309812.

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 21890357 - 2¹⁰ = 21889333 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 (21890317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17753 + ... + 18945.

It is an arithmetic number, because the mean of its divisors is an integer number (2793960).

Almost surely, 2^21890357 is an apocalyptic number.

It is an amenable number.

21890357 is a deficient number, since it is larger than the sum of its proper divisors (461323).

21890357 is a wasteful number, since it uses less digits than its factorization.

21890357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1563.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 21890357 is about 4678.7131777872. The cubic root of 21890357 is about 279.7376667105.

The spelling of 21890357 in words is "twenty-one million, eight hundred ninety thousand, three hundred fifty-seven".