21101431 has 8 divisors (see below), whose sum is σ = 22905344. Its totient is φ = 19323360.

The previous prime is 21101411. The next prime is 21101441. The reversal of 21101431 is 13410112.

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 21101431 - 2¹¹ = 21099383 is a prime.

It is a super-2 number, since 2×21101431² = 890540780495522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101401) 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, 4740 + ... + 8041.

It is an arithmetic number, because the mean of its divisors is an integer number (2863168).

Almost surely, 2^21101431 is an apocalyptic number.

21101431 is a deficient number, since it is larger than the sum of its proper divisors (1803913).

21101431 is a wasteful number, since it uses less digits than its factorization.

21101431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12921.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 21101431 is about 4593.6293929746. The cubic root of 21101431 is about 276.3358955678.

Adding to 21101431 its reverse (13410112), we get a palindrome (34511543).

The spelling of 21101431 in words is "twenty-one million, one hundred one thousand, four hundred thirty-one".