145855531 has 4 divisors (see below), whose sum is σ = 146969064. Its totient is φ = 144742000.

The previous prime is 145855499. The next prime is 145855537. The reversal of 145855531 is 135558541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135558541 = 661 ⋅205081.

It is a cyclic number.

It is not a de Polignac number, because 145855531 - 2⁵ = 145855499 is a prime.

It is a super-2 number, since 2×145855531² = 42547671846583922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145855537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 556570 + ... + 556831.

It is an arithmetic number, because the mean of its divisors is an integer number (36742266).

Almost surely, 2^145855531 is an apocalyptic number.

145855531 is a deficient number, since it is larger than the sum of its proper divisors (1113533).

145855531 is a wasteful number, since it uses less digits than its factorization.

145855531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1113532.

The product of its digits is 60000, while the sum is 37.

The square root of 145855531 is about 12077.0663242362. The cubic root of 145855531 is about 526.3900048203.

The spelling of 145855531 in words is "one hundred forty-five million, eight hundred fifty-five thousand, five hundred thirty-one".