145665551 has 4 divisors (see below), whose sum is σ = 145984752. Its totient is φ = 145346352.

The previous prime is 145665547. The next prime is 145665557. The reversal of 145665551 is 155566541.

It is a happy number.

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 145665551 - 2² = 145665547 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145665557) 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, 158915 + ... + 159828.

It is an arithmetic number, because the mean of its divisors is an integer number (36496188).

Almost surely, 2^145665551 is an apocalyptic number.

145665551 is a deficient number, since it is larger than the sum of its proper divisors (319201).

145665551 is an equidigital number, since it uses as much as digits as its factorization.

145665551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319200.

The product of its digits is 90000, while the sum is 38.

The square root of 145665551 is about 12069.1984406588. The cubic root of 145665551 is about 526.1613607119.

The spelling of 145665551 in words is "one hundred forty-five million, six hundred sixty-five thousand, five hundred fifty-one".