145681961 has 2 divisors, whose sum is σ = 145681962. Its totient is φ = 145681960.

The previous prime is 145681933. The next prime is 145681967. The reversal of 145681961 is 169186541.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137616361 + 8065600 = 11731^2 + 2840^2 .

It is a cyclic number.

It is not a de Polignac number, because 145681961 - 2¹⁰ = 145680937 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (145681967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72840980 + 72840981.

It is an arithmetic number, because the mean of its divisors is an integer number (72840981).

Almost surely, 2^145681961 is an apocalyptic number.

It is an amenable number.

145681961 is a deficient number, since it is larger than the sum of its proper divisors (1).

145681961 is an equidigital number, since it uses as much as digits as its factorization.

145681961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 41.

The square root of 145681961 is about 12069.8782512501. The cubic root of 145681961 is about 526.1811182630.

The spelling of 145681961 in words is "one hundred forty-five million, six hundred eighty-one thousand, nine hundred sixty-one".