145661291 has 4 divisors (see below), whose sum is σ = 147103584. Its totient is φ = 144219000.

The previous prime is 145661279. The next prime is 145661293. The reversal of 145661291 is 192166541.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 145661291 - 2²² = 141466987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145661293) 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, 720995 + ... + 721196.

It is an arithmetic number, because the mean of its divisors is an integer number (36775896).

Almost surely, 2^145661291 is an apocalyptic number.

145661291 is a deficient number, since it is larger than the sum of its proper divisors (1442293).

145661291 is a wasteful number, since it uses less digits than its factorization.

145661291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1442292.

The product of its digits is 12960, while the sum is 35.

The square root of 145661291 is about 12069.0219570601. The cubic root of 145661291 is about 526.1562314524.

The spelling of 145661291 in words is "one hundred forty-five million, six hundred sixty-one thousand, two hundred ninety-one".