21514381 has 12 divisors (see below), whose sum is σ = 25639740. Its totient is φ = 17989440.

The previous prime is 21514369. The next prime is 21514387. The reversal of 21514381 is 18341512.

It can be written as a sum of positive squares in 2 ways, for example, as 11055625 + 10458756 = 3325^2 + 3234^2 .

It is not a de Polignac number, because 21514381 - 2¹¹ = 21512333 is a prime.

It is a super-2 number, since 2×21514381² = 925737179626322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21514387) 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, 3346 + ... + 7363.

It is an arithmetic number, because the mean of its divisors is an integer number (2136645).

Almost surely, 2^21514381 is an apocalyptic number.

It is an amenable number.

21514381 is a deficient number, since it is larger than the sum of its proper divisors (4125359).

21514381 is a wasteful number, since it uses less digits than its factorization.

21514381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10764 (or 10757 counting only the distinct ones).

The product of its digits is 960, while the sum is 25.

The square root of 21514381 is about 4638.3597316293. The cubic root of 21514381 is about 278.1268722005.

Adding to 21514381 its reverse (18341512), we get a palindrome (39855893).

The spelling of 21514381 in words is "twenty-one million, five hundred fourteen thousand, three hundred eighty-one".