721385133 has 24 divisors (see below), whose sum is σ = 1149142848. Its totient is φ = 394291392.

The previous prime is 721385131. The next prime is 721385183. The reversal of 721385133 is 331583127.

It is not a de Polignac number, because 721385133 - 2¹ = 721385131 is a prime.

It is a super-2 number, since 2×721385133² = 1040793020226855378, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 721385094 and 721385103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721385131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21360 + ... + 43577.

It is an arithmetic number, because the mean of its divisors is an integer number (47880952).

Almost surely, 2^721385133 is an apocalyptic number.

It is an amenable number.

721385133 is a deficient number, since it is larger than the sum of its proper divisors (427757715).

721385133 is a wasteful number, since it uses less digits than its factorization.

721385133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64993 (or 64970 counting only the distinct ones).

The product of its digits is 15120, while the sum is 33.

The square root of 721385133 is about 26858.6137579734. The cubic root of 721385133 is about 896.8553349871.

The spelling of 721385133 in words is "seven hundred twenty-one million, three hundred eighty-five thousand, one hundred thirty-three".