21480137 has 8 divisors (see below), whose sum is σ = 25616256. Its totient is φ = 17610912.

The previous prime is 21480131. The next prime is 21480157. The reversal of 21480137 is 73108412.

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 21480137 - 2⁶ = 21480073 is a prime.

It is a super-2 number, since 2×21480137² = 922792571077538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21480131) 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, 66548 + ... + 66869.

It is an arithmetic number, because the mean of its divisors is an integer number (3202032).

Almost surely, 2^21480137 is an apocalyptic number.

It is an amenable number.

21480137 is a deficient number, since it is larger than the sum of its proper divisors (4136119).

21480137 is a wasteful number, since it uses less digits than its factorization.

21480137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133447.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 21480137 is about 4634.6668704450. Note that the first 3 decimals coincide. The cubic root of 21480137 is about 277.9792308898.

Adding to 21480137 its reverse (73108412), we get a palindrome (94588549).

The spelling of 21480137 in words is "twenty-one million, four hundred eighty thousand, one hundred thirty-seven".