21372735 has 8 divisors (see below), whose sum is σ = 34196400. Its totient is φ = 11398784.

The previous prime is 21372719. The next prime is 21372737. The reversal of 21372735 is 53727312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21372735 - 2⁴ = 21372719 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21372737) 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, 712410 + ... + 712439.

It is an arithmetic number, because the mean of its divisors is an integer number (4274550).

Almost surely, 2^21372735 is an apocalyptic number.

21372735 is a deficient number, since it is larger than the sum of its proper divisors (12823665).

21372735 is a wasteful number, since it uses less digits than its factorization.

21372735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1424857.

The product of its digits is 8820, while the sum is 30.

The square root of 21372735 is about 4623.0655413913. The cubic root of 21372735 is about 277.5151521635.

It can be divided in two parts, 2137273 and 5, that added together give a triangular number (2137278 = T₂₀₆₇).

The spelling of 21372735 in words is "twenty-one million, three hundred seventy-two thousand, seven hundred thirty-five".