21201431 has 8 divisors (see below), whose sum is σ = 22873104. Its totient is φ = 19576960.

The previous prime is 21201421. The next prime is 21201443. The reversal of 21201431 is 13410212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201431 is a prime.

It is a super-2 number, since 2×21201431² = 899001352895522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201421) 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, 10865 + ... + 12666.

It is an arithmetic number, because the mean of its divisors is an integer number (2859138).

Almost surely, 2^21201431 is an apocalyptic number.

21201431 is a deficient number, since it is larger than the sum of its proper divisors (1671673).

21201431 is a wasteful number, since it uses less digits than its factorization.

21201431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23601.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21201431 is about 4604.5011673362. The cubic root of 21201431 is about 276.7717278126.

Adding to 21201431 its reverse (13410212), we get a palindrome (34611643).

The spelling of 21201431 in words is "twenty-one million, two hundred one thousand, four hundred thirty-one".