720643545 has 24 divisors (see below), whose sum is σ = 1250997696. Its totient is φ = 383764128.

The previous prime is 720643529. The next prime is 720643559. The reversal of 720643545 is 545346027.

720643545 is a `hidden beast` number, since 7 + 2 + 0 + 643 + 5 + 4 + 5 = 666.

It is not a de Polignac number, because 720643545 - 2⁴ = 720643529 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19012 + ... + 42458.

It is an arithmetic number, because the mean of its divisors is an integer number (52124904).

Almost surely, 2^720643545 is an apocalyptic number.

It is an amenable number.

720643545 is a deficient number, since it is larger than the sum of its proper divisors (530354151).

720643545 is a wasteful number, since it uses less digits than its factorization.

720643545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24141 (or 24138 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 36.

The square root of 720643545 is about 26844.8048046545. The cubic root of 720643545 is about 896.5479054963.

The spelling of 720643545 in words is "seven hundred twenty million, six hundred forty-three thousand, five hundred forty-five".