1545505981 has 2 divisors, whose sum is σ = 1545505982. Its totient is φ = 1545505980.

The previous prime is 1545505937. The next prime is 1545506041. The reversal of 1545505981 is 1895055451.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 876456025 + 669049956 = 29605^2 + 25866^2 .

It is a cyclic number.

It is not a de Polignac number, because 1545505981 - 2⁹ = 1545505469 is a prime.

It is a super-2 number, since 2×1545505981² = 4777177474613544722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1545505931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 772752990 + 772752991.

It is an arithmetic number, because the mean of its divisors is an integer number (772752991).

Almost surely, 2^1545505981 is an apocalyptic number.

It is an amenable number.

1545505981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1545505981 is an equidigital number, since it uses as much as digits as its factorization.

1545505981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180000, while the sum is 43.

The square root of 1545505981 is about 39312.9238419123. The cubic root of 1545505981 is about 1156.1749706717.

The spelling of 1545505981 in words is "one billion, five hundred forty-five million, five hundred five thousand, nine hundred eighty-one".