21350791 has 16 divisors (see below), whose sum is σ = 27272448. Its totient is φ = 16228800.

The previous prime is 21350753. The next prime is 21350803. The reversal of 21350791 is 19705312.

It is a de Polignac number, because none of the positive numbers 2^k-21350791 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21350701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 225 + ... + 6538.

It is an arithmetic number, because the mean of its divisors is an integer number (1704528).

Almost surely, 2^21350791 is an apocalyptic number.

21350791 is a deficient number, since it is larger than the sum of its proper divisors (5921657).

21350791 is a wasteful number, since it uses less digits than its factorization.

21350791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6822.

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

The square root of 21350791 is about 4620.6916148992. The cubic root of 21350791 is about 277.4201420509.

The spelling of 21350791 in words is "twenty-one million, three hundred fifty thousand, seven hundred ninety-one".