537661 has 2 divisors, whose sum is σ = 537662. Its totient is φ = 537660.

The previous prime is 537637. The next prime is 537673. The reversal of 537661 is 166735.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 532900 + 4761 = 730^2 + 69^2 .

It is a cyclic number.

It is not a de Polignac number, because 537661 - 2¹⁵ = 504893 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (537611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 268830 + 268831.

It is an arithmetic number, because the mean of its divisors is an integer number (268831).

2⁵³⁷⁶⁶¹ is an apocalyptic number.

It is an amenable number.

537661 is a deficient number, since it is larger than the sum of its proper divisors (1).

537661 is an equidigital number, since it uses as much as digits as its factorization.

537661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780, while the sum is 28.

The square root of 537661 is about 733.2537077983. The cubic root of 537661 is about 81.3147838345.

The spelling of 537661 in words is "five hundred thirty-seven thousand, six hundred sixty-one".