21061337 has 16 divisors (see below), whose sum is σ = 24036480. Its totient is φ = 18278400.

The previous prime is 21061309. The next prime is 21061343. The reversal of 21061337 is 73316012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21061337 - 2⁸ = 21061081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21061037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32537 + ... + 33177.

It is an arithmetic number, because the mean of its divisors is an integer number (1502280).

Almost surely, 2^21061337 is an apocalyptic number.

It is an amenable number.

21061337 is a deficient number, since it is larger than the sum of its proper divisors (2975143).

21061337 is a wasteful number, since it uses less digits than its factorization.

21061337 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 784.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 21061337 is about 4589.2632306286. The cubic root of 21061337 is about 276.1607662760.

Adding to 21061337 its reverse (73316012), we get a palindrome (94377349).

It can be divided in two parts, 2106 and 1337, that added together give a palindrome (3443).

The spelling of 21061337 in words is "twenty-one million, sixty-one thousand, three hundred thirty-seven".