21431607 has 16 divisors (see below), whose sum is σ = 29956608. Its totient is φ = 13603040.

The previous prime is 21431593. The next prime is 21431623. The reversal of 21431607 is 70613412.

It is a cyclic number.

It is not a de Polignac number, because 21431607 - 2¹¹ = 21429559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17557 + ... + 18737.

It is an arithmetic number, because the mean of its divisors is an integer number (1872288).

Almost surely, 2^21431607 is an apocalyptic number.

21431607 is a deficient number, since it is larger than the sum of its proper divisors (8525001).

21431607 is a wasteful number, since it uses less digits than its factorization.

21431607 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1470.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21431607 is about 4629.4283664401. The cubic root of 21431607 is about 277.7697271919.

The spelling of 21431607 in words is "twenty-one million, four hundred thirty-one thousand, six hundred seven".