721155285 has 16 divisors (see below), whose sum is σ = 1282054080. Its totient is φ = 384616080.

The previous prime is 721155277. The next prime is 721155287. The reversal of 721155285 is 582551127.

721155285 is a `hidden beast` number, since 7 + 21 + 1 + 552 + 85 = 666.

It is not a de Polignac number, because 721155285 - 2³ = 721155277 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721155287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2670811 + ... + 2671080.

It is an arithmetic number, because the mean of its divisors is an integer number (80128380).

Almost surely, 2^721155285 is an apocalyptic number.

It is an amenable number.

721155285 is a deficient number, since it is larger than the sum of its proper divisors (560898795).

721155285 is a wasteful number, since it uses less digits than its factorization.

721155285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5341905 (or 5341899 counting only the distinct ones).

The product of its digits is 28000, while the sum is 36.

The square root of 721155285 is about 26854.3345663228. The cubic root of 721155285 is about 896.7600727418.

The spelling of 721155285 in words is "seven hundred twenty-one million, one hundred fifty-five thousand, two hundred eighty-five".