21480437 has 4 divisors (see below), whose sum is σ = 23433216. Its totient is φ = 19527660.

The previous prime is 21480397. The next prime is 21480439. The reversal of 21480437 is 73408412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21480437 - 2⁸ = 21480181 is a prime.

It is a super-2 number, since 2×21480437² = 922818347421938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21480439) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 976373 + ... + 976394.

It is an arithmetic number, because the mean of its divisors is an integer number (5858304).

Almost surely, 2^21480437 is an apocalyptic number.

It is an amenable number.

21480437 is a deficient number, since it is larger than the sum of its proper divisors (1952779).

21480437 is a wasteful number, since it uses less digits than its factorization.

21480437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1952778.

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 21480437 is about 4634.6992351176. The cubic root of 21480437 is about 277.9805250060.

Adding to 21480437 its reverse (73408412), we get a palindrome (94888849).

The spelling of 21480437 in words is "twenty-one million, four hundred eighty thousand, four hundred thirty-seven".