145740721 has 8 divisors (see below), whose sum is σ = 166864320. Its totient is φ = 124693008.

The previous prime is 145740713. The next prime is 145740731. The reversal of 145740721 is 127047541.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 145740721 - 2³ = 145740713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (145740731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14791 + ... + 22588.

It is an arithmetic number, because the mean of its divisors is an integer number (20858040).

Almost surely, 2^145740721 is an apocalyptic number.

It is an amenable number.

145740721 is a deficient number, since it is larger than the sum of its proper divisors (21123599).

145740721 is an equidigital number, since it uses as much as digits as its factorization.

145740721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37943.

The product of its (nonzero) digits is 7840, while the sum is 31.

The square root of 145740721 is about 12072.3121646187. The cubic root of 145740721 is about 526.2518528191.

The spelling of 145740721 in words is "one hundred forty-five million, seven hundred forty thousand, seven hundred twenty-one".