21340039 has 12 divisors (see below), whose sum is σ = 24931800. Its totient is φ = 18212208.

The previous prime is 21340019. The next prime is 21340051. The reversal of 21340039 is 93004312.

It is not a de Polignac number, because 21340039 - 2¹³ = 21331847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21340019) 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, 12372 + ... + 13990.

It is an arithmetic number, because the mean of its divisors is an integer number (2077650).

Almost surely, 2^21340039 is an apocalyptic number.

21340039 is a deficient number, since it is larger than the sum of its proper divisors (3591761).

21340039 is a wasteful number, since it uses less digits than its factorization.

21340039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1902 (or 1895 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 21340039 is about 4619.5280061928. The cubic root of 21340039 is about 277.3735657560.

The spelling of 21340039 in words is "twenty-one million, three hundred forty thousand, thirty-nine".