21253934 has 16 divisors (see below), whose sum is σ = 34586160. Its totient is φ = 9737280.

The previous prime is 21253931. The next prime is 21253937. The reversal of 21253934 is 43935212.

It is a Cunningham number, because it is equal to 277³+1.

It is an interprime number because it is at equal distance from previous prime (21253931) and next prime (21253937).

It is a junction number, because it is equal to n+sod(n) for n = 21253897 and 21253906.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253931) 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, 674 + ... + 6554.

It is an arithmetic number, because the mean of its divisors is an integer number (2161635).

Almost surely, 2^21253934 is an apocalyptic number.

21253934 is a deficient number, since it is larger than the sum of its proper divisors (13332226).

21253934 is a wasteful number, since it uses less digits than its factorization.

21253934 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6035.

The product of its digits is 6480, while the sum is 29.

The square root of 21253934 is about 4610.1989111100. The cubic root of 21253934 is about 277.0000043443. Note that the first 5 decimals are identical.

The spelling of 21253934 in words is "twenty-one million, two hundred fifty-three thousand, nine hundred thirty-four".