13740021 has 18 divisors (see below), whose sum is σ = 20951190. Its totient is φ = 8675856.

The previous prime is 13740019. The next prime is 13740047. The reversal of 13740021 is 12004731.

It can be written as a sum of positive squares in only one way, i.e., 13727025 + 12996 = 3705^2 + 114^2 .

It is not a de Polignac number, because 13740021 - 2¹ = 13740019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13739976 and 13740003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13740421) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1135 + ... + 5363.

It is an arithmetic number, because the mean of its divisors is an integer number (1163955).

Almost surely, 2^13740021 is an apocalyptic number.

It is an amenable number.

13740021 is a deficient number, since it is larger than the sum of its proper divisors (7211169).

13740021 is a wasteful number, since it uses less digits than its factorization.

13740021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4273 (or 4251 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 13740021 is about 3706.7534312387. The cubic root of 13740021 is about 239.5130229740.

Adding to 13740021 its reverse (12004731), we get a palindrome (25744752).

The spelling of 13740021 in words is "thirteen million, seven hundred forty thousand, twenty-one".