21190357 has 4 divisors (see below), whose sum is σ = 21683200. Its totient is φ = 20697516.

The previous prime is 21190349. The next prime is 21190409. The reversal of 21190357 is 75309112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21190357 - 2³ = 21190349 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 (21190327) 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 3 ways as a sum of consecutive naturals, for example, 246357 + ... + 246442.

It is an arithmetic number, because the mean of its divisors is an integer number (5420800).

Almost surely, 2^21190357 is an apocalyptic number.

It is an amenable number.

21190357 is a deficient number, since it is larger than the sum of its proper divisors (492843).

21190357 is an equidigital number, since it uses as much as digits as its factorization.

21190357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492842.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 21190357 is about 4603.2984912995. The cubic root of 21190357 is about 276.7235313189.

Adding to 21190357 its reverse (75309112), we get a palindrome (96499469).

The spelling of 21190357 in words is "twenty-one million, one hundred ninety thousand, three hundred fifty-seven".