1546221661 has 2 divisors, whose sum is σ = 1546221662. Its totient is φ = 1546221660.

The previous prime is 1546221619. The next prime is 1546221671. The reversal of 1546221661 is 1661226451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1543311225 + 2910436 = 39285^2 + 1706^2 .

It is a cyclic number.

It is not a de Polignac number, because 1546221661 - 2⁷ = 1546221533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1546221671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 773110830 + 773110831.

It is an arithmetic number, because the mean of its divisors is an integer number (773110831).

Almost surely, 2^1546221661 is an apocalyptic number.

It is an amenable number.

1546221661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1546221661 is an equidigital number, since it uses as much as digits as its factorization.

1546221661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 34.

The square root of 1546221661 is about 39322.0251385912. The cubic root of 1546221661 is about 1156.3534070809.

The spelling of 1546221661 in words is "one billion, five hundred forty-six million, two hundred twenty-one thousand, six hundred sixty-one".