661504043 has 2 divisors, whose sum is σ = 661504044. Its totient is φ = 661504042.

The previous prime is 661504031. The next prime is 661504073. The reversal of 661504043 is 340405166.

It is a happy number.

661504043 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661504043 - 2⁶ = 661503979 is a prime.

It is equal to p_34360319 and since 661504043 and 34360319 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 661503997 and 661504015.

It is not a weakly prime, because it can be changed into another prime (661504003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330752021 + 330752022.

It is an arithmetic number, because the mean of its divisors is an integer number (330752022).

Almost surely, 2^661504043 is an apocalyptic number.

661504043 is a deficient number, since it is larger than the sum of its proper divisors (1).

661504043 is an equidigital number, since it uses as much as digits as its factorization.

661504043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 661504043 is about 25719.7208966194. The cubic root of 661504043 is about 871.3196351572.

The spelling of 661504043 in words is "six hundred sixty-one million, five hundred four thousand, forty-three".