21397935 has 48 divisors (see below), whose sum is σ = 38790144. Its totient is φ = 10048896.

The previous prime is 21397931. The next prime is 21397949. The reversal of 21397935 is 53979312.

It is not a de Polignac number, because 21397935 - 2² = 21397931 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a junction number, because it is equal to n+sod(n) for n = 21397893 and 21397902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21397931) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 58122 + ... + 58488.

It is an arithmetic number, because the mean of its divisors is an integer number (808128).

Almost surely, 2^21397935 is an apocalyptic number.

21397935 is a deficient number, since it is larger than the sum of its proper divisors (17392209).

21397935 is a wasteful number, since it uses less digits than its factorization.

21397935 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424 (or 411 counting only the distinct ones).

The product of its digits is 51030, while the sum is 39.

The square root of 21397935 is about 4625.7902027654. The cubic root of 21397935 is about 277.6241794681.

The spelling of 21397935 in words is "twenty-one million, three hundred ninety-seven thousand, nine hundred thirty-five".