145039781 has 2 divisors, whose sum is σ = 145039782. Its totient is φ = 145039780.

The previous prime is 145039777. The next prime is 145039799. The reversal of 145039781 is 187930541.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121903681 + 23136100 = 11041^2 + 4810^2 .

It is an emirp because it is prime and its reverse (187930541) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 145039781 - 2² = 145039777 is a prime.

It is a super-2 number, since 2×145039781² = 42073076145055922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (145039381) 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, 72519890 + 72519891.

It is an arithmetic number, because the mean of its divisors is an integer number (72519891).

Almost surely, 2^145039781 is an apocalyptic number.

It is an amenable number.

145039781 is a deficient number, since it is larger than the sum of its proper divisors (1).

145039781 is an equidigital number, since it uses as much as digits as its factorization.

145039781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 145039781 is about 12043.2462816302. The cubic root of 145039781 is about 525.4068272193.

The spelling of 145039781 in words is "one hundred forty-five million, thirty-nine thousand, seven hundred eighty-one".