21035407 has 4 divisors (see below), whose sum is σ = 21051576. Its totient is φ = 21019240.

The previous prime is 21035401. The next prime is 21035429. The reversal of 21035407 is 70453012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21035407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21035401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5944 + ... + 8797.

It is an arithmetic number, because the mean of its divisors is an integer number (5262894).

Almost surely, 2^21035407 is an apocalyptic number.

21035407 is a deficient number, since it is larger than the sum of its proper divisors (16169).

21035407 is a wasteful number, since it uses less digits than its factorization.

21035407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16168.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 21035407 is about 4586.4372883536. The cubic root of 21035407 is about 276.0473864937.

Adding to 21035407 its reverse (70453012), we get a palindrome (91488419).

The spelling of 21035407 in words is "twenty-one million, thirty-five thousand, four hundred seven".