145631281 has 4 divisors (see below), whose sum is σ = 146778112. Its totient is φ = 144484452.

The previous prime is 145631279. The next prime is 145631287. The reversal of 145631281 is 182136541.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 182136541 = 199 ⋅915259.

It is a cyclic number.

It is not a de Polignac number, because 145631281 - 2¹ = 145631279 is a prime.

It is a super-2 number, since 2×145631281² = 42416940011401922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145631287) 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 in 3 ways as a sum of consecutive naturals, for example, 573225 + ... + 573478.

It is an arithmetic number, because the mean of its divisors is an integer number (36694528).

Almost surely, 2^145631281 is an apocalyptic number.

It is an amenable number.

145631281 is a deficient number, since it is larger than the sum of its proper divisors (1146831).

145631281 is a wasteful number, since it uses less digits than its factorization.

145631281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1146830.

The product of its digits is 5760, while the sum is 31.

The square root of 145631281 is about 12067.7786274028. The cubic root of 145631281 is about 526.1200950318.

The spelling of 145631281 in words is "one hundred forty-five million, six hundred thirty-one thousand, two hundred eighty-one".