16400537 has 4 divisors (see below), whose sum is σ = 16412340. Its totient is φ = 16388736.

The previous prime is 16400513. The next prime is 16400539. The reversal of 16400537 is 73500461.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14409616 + 1990921 = 3796^2 + 1411^2 .

It is a cyclic number.

It is not a de Polignac number, because 16400537 - 2⁶ = 16400473 is a prime.

It is a super-2 number, since 2×16400537² = 537955227776738, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16400539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3488 + ... + 6705.

It is an arithmetic number, because the mean of its divisors is an integer number (4103085).

Almost surely, 2^16400537 is an apocalyptic number.

It is an amenable number.

16400537 is a deficient number, since it is larger than the sum of its proper divisors (11803).

16400537 is a wasteful number, since it uses less digits than its factorization.

16400537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11802.

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 16400537 is about 4049.7576470698. The cubic root of 16400537 is about 254.0695915706.

Adding to 16400537 its reverse (73500461), we get a palindrome (89900998).

The spelling of 16400537 in words is "sixteen million, four hundred thousand, five hundred thirty-seven".