721006755 has 16 divisors (see below), whose sum is σ = 1318412544. Its totient is φ = 329603040.

The previous prime is 721006733. The next prime is 721006789. The reversal of 721006755 is 557600127.

It is not a de Polignac number, because 721006755 - 2¹¹ = 721004707 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3433261 + ... + 3433470.

It is an arithmetic number, because the mean of its divisors is an integer number (82400784).

Almost surely, 2^721006755 is an apocalyptic number.

721006755 is a deficient number, since it is larger than the sum of its proper divisors (597405789).

721006755 is a wasteful number, since it uses less digits than its factorization.

721006755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6866746.

The product of its (nonzero) digits is 14700, while the sum is 33.

The square root of 721006755 is about 26851.5689485736. The cubic root of 721006755 is about 896.6985025910.

The spelling of 721006755 in words is "seven hundred twenty-one million, six thousand, seven hundred fifty-five".