21131514 has 24 divisors (see below), whose sum is σ = 47023860. Its totient is φ = 6853248.

The previous prime is 21131507. The next prime is 21131519. The reversal of 21131514 is 41513112.

21131514 is a `hidden beast` number, since 21 + 131 + 514 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 16136289 + 4995225 = 4017^2 + 2235^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21131519) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15199 + ... + 16530.

Almost surely, 2^21131514 is an apocalyptic number.

21131514 is an abundant number, since it is smaller than the sum of its proper divisors (25892346).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21131514 is a wasteful number, since it uses less digits than its factorization.

21131514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31774 (or 31771 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 21131514 is about 4596.9026528740. The cubic root of 21131514 is about 276.4671515226.

Adding to 21131514 its reverse (41513112), we get a palindrome (62644626).

The spelling of 21131514 in words is "twenty-one million, one hundred thirty-one thousand, five hundred fourteen".