21135974 has 4 divisors (see below), whose sum is σ = 31703964. Its totient is φ = 10567986.

The previous prime is 21135971. The next prime is 21135997. The reversal of 21135974 is 47953112.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21135974.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21135971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5283992 + ... + 5283995.

It is an arithmetic number, because the mean of its divisors is an integer number (7925991).

Almost surely, 2^21135974 is an apocalyptic number.

21135974 is a deficient number, since it is larger than the sum of its proper divisors (10567990).

21135974 is a wasteful number, since it uses less digits than its factorization.

21135974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10567989.

The product of its digits is 7560, while the sum is 32.

The square root of 21135974 is about 4597.3877365304. The cubic root of 21135974 is about 276.4866004644.

The spelling of 21135974 in words is "twenty-one million, one hundred thirty-five thousand, nine hundred seventy-four".