661547 has 2 divisors, whose sum is σ = 661548. Its totient is φ = 661546.

The previous prime is 661541. The next prime is 661553. The reversal of 661547 is 745166.

It is a balanced prime because it is at equal distance from previous prime (661541) and next prime (661553).

It is a cyclic number.

It is not a de Polignac number, because 661547 - 2⁶ = 661483 is a prime.

It is not a weakly prime, because it can be changed into another prime (661541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330773 + 330774.

It is an arithmetic number, because the mean of its divisors is an integer number (330774).

2⁶⁶¹⁵⁴⁷ is an apocalyptic number.

661547 is a deficient number, since it is larger than the sum of its proper divisors (1).

661547 is an equidigital number, since it uses as much as digits as its factorization.

661547 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 29.

The square root of 661547 is about 813.3553958756. The cubic root of 661547 is about 87.1338495444.

The spelling of 661547 in words is "six hundred sixty-one thousand, five hundred forty-seven".