661153403 has 2 divisors, whose sum is σ = 661153404. Its totient is φ = 661153402.

The previous prime is 661153357. The next prime is 661153439. The reversal of 661153403 is 304351166.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661153403 - 2¹⁰ = 661152379 is a prime.

It is not a weakly prime, because it can be changed into another prime (661153453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330576701 + 330576702.

It is an arithmetic number, because the mean of its divisors is an integer number (330576702).

Almost surely, 2^661153403 is an apocalyptic number.

661153403 is a deficient number, since it is larger than the sum of its proper divisors (1).

661153403 is an equidigital number, since it uses as much as digits as its factorization.

661153403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 661153403 is about 25712.9034338793. The cubic root of 661153403 is about 871.1656559953.

The spelling of 661153403 in words is "six hundred sixty-one million, one hundred fifty-three thousand, four hundred three".