21797835 has 16 divisors (see below), whose sum is σ = 34937376. Its totient is φ = 11605248.

The previous prime is 21797833. The next prime is 21797843. The reversal of 21797835 is 53879712.

It is not a de Polignac number, because 21797835 - 2¹ = 21797833 is a prime.

It is a super-2 number, since 2×21797835² = 950291221374450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21797833) 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, 12327 + ... + 13983.

It is an arithmetic number, because the mean of its divisors is an integer number (2183586).

Almost surely, 2^21797835 is an apocalyptic number.

21797835 is a deficient number, since it is larger than the sum of its proper divisors (13139541).

21797835 is a wasteful number, since it uses less digits than its factorization.

21797835 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2542.

The product of its digits is 105840, while the sum is 42.

The square root of 21797835 is about 4668.8151601879. The cubic root of 21797835 is about 279.3429961488.

The spelling of 21797835 in words is "twenty-one million, seven hundred ninety-seven thousand, eight hundred thirty-five".