145731986 has 4 divisors (see below), whose sum is σ = 218597982. Its totient is φ = 72865992.

The previous prime is 145731907. The next prime is 145731997. The reversal of 145731986 is 689137541.

145731986 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 689137541 = 6701 ⋅102841.

It can be written as a sum of positive squares in only one way, i.e., 106481761 + 39250225 = 10319^2 + 6265^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36432995 + ... + 36432998.

Almost surely, 2^145731986 is an apocalyptic number.

145731986 is a deficient number, since it is larger than the sum of its proper divisors (72865996).

145731986 is an equidigital number, since it uses as much as digits as its factorization.

145731986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72865995.

The product of its digits is 181440, while the sum is 44.

The square root of 145731986 is about 12071.9503809451. The cubic root of 145731986 is about 526.2413389381.

The spelling of 145731986 in words is "one hundred forty-five million, seven hundred thirty-one thousand, nine hundred eighty-six".