21016037 has 16 divisors (see below), whose sum is σ = 25149312. Its totient is φ = 17184960.

The previous prime is 21016031. The next prime is 21016049. The reversal of 21016037 is 73061012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21016037 - 2¹⁰ = 21015013 is a prime.

It is a super-2 number, since 2×21016037² = 883347622370738, 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 (21016031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12962 + ... + 14492.

It is an arithmetic number, because the mean of its divisors is an integer number (1571832).

Almost surely, 2^21016037 is an apocalyptic number.

It is an amenable number.

21016037 is a deficient number, since it is larger than the sum of its proper divisors (4133275).

21016037 is a wasteful number, since it uses less digits than its factorization.

21016037 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1628.

The product of its (nonzero) digits is 252, while the sum is 20.

The square root of 21016037 is about 4584.3251411740. The cubic root of 21016037 is about 275.9626297159.

Adding to 21016037 its reverse (73061012), we get a palindrome (94077049).

The spelling of 21016037 in words is "twenty-one million, sixteen thousand, thirty-seven".