1661254447 has 2 divisors, whose sum is σ = 1661254448. Its totient is φ = 1661254446.

The previous prime is 1661254411. The next prime is 1661254459. The reversal of 1661254447 is 7444521661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1661254447 - 2²³ = 1652865839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661254247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830627223 + 830627224.

It is an arithmetic number, because the mean of its divisors is an integer number (830627224).

Almost surely, 2^1661254447 is an apocalyptic number.

1661254447 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661254447 is an equidigital number, since it uses as much as digits as its factorization.

1661254447 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 40.

The square root of 1661254447 is about 40758.4892629744. The cubic root of 1661254447 is about 1184.3463306060.

The spelling of 1661254447 in words is "one billion, six hundred sixty-one million, two hundred fifty-four thousand, four hundred forty-seven".