145621109 has 2 divisors, whose sum is σ = 145621110. Its totient is φ = 145621108.

The previous prime is 145621097. The next prime is 145621123. The reversal of 145621109 is 901126541.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145202500 + 418609 = 12050^2 + 647^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145621109 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (145621139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72810554 + 72810555.

It is an arithmetic number, because the mean of its divisors is an integer number (72810555).

Almost surely, 2^145621109 is an apocalyptic number.

It is an amenable number.

145621109 is a deficient number, since it is larger than the sum of its proper divisors (1).

145621109 is an equidigital number, since it uses as much as digits as its factorization.

145621109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 145621109 is about 12067.3571671680. The cubic root of 145621109 is about 526.1078453325.

The spelling of 145621109 in words is "one hundred forty-five million, six hundred twenty-one thousand, one hundred nine".