21395836 has 24 divisors (see below), whose sum is σ = 46682496. Its totient is φ = 8335920.

The previous prime is 21395831. The next prime is 21395849. The reversal of 21395836 is 63859312.

It is a junction number, because it is equal to n+sod(n) for n = 21395795 and 21395804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21395831) 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, 34426 + ... + 35041.

It is an arithmetic number, because the mean of its divisors is an integer number (1945104).

Almost surely, 2^21395836 is an apocalyptic number.

It is an amenable number.

21395836 is an abundant number, since it is smaller than the sum of its proper divisors (25286660).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21395836 is a wasteful number, since it uses less digits than its factorization.

21395836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69489 (or 69487 counting only the distinct ones).

The product of its digits is 38880, while the sum is 37.

The square root of 21395836 is about 4625.5633170458. The cubic root of 21395836 is about 277.6151014549.

The spelling of 21395836 in words is "twenty-one million, three hundred ninety-five thousand, eight hundred thirty-six".