721284537 has 16 divisors (see below), whose sum is σ = 992806848. Its totient is φ = 465507840.

The previous prime is 721284521. The next prime is 721284541. The reversal of 721284537 is 735482127.

It is not a de Polignac number, because 721284537 - 2⁴ = 721284521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 721284495 and 721284504.

It is not an unprimeable number, because it can be changed into a prime (721286537) 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, 10164 + ... + 39317.

It is an arithmetic number, because the mean of its divisors is an integer number (62050428).

Almost surely, 2^721284537 is an apocalyptic number.

It is an amenable number.

721284537 is a deficient number, since it is larger than the sum of its proper divisors (271522311).

721284537 is a wasteful number, since it uses less digits than its factorization.

721284537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49640.

The product of its digits is 94080, while the sum is 39.

The square root of 721284537 is about 26856.7409973735. The cubic root of 721284537 is about 896.8136447030.

The spelling of 721284537 in words is "seven hundred twenty-one million, two hundred eighty-four thousand, five hundred thirty-seven".