721040097 has 4 divisors (see below), whose sum is σ = 961386800. Its totient is φ = 480693396.

The previous prime is 721040093. The next prime is 721040119. The reversal of 721040097 is 790040127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 721040097 - 2² = 721040093 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721040093) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120173347 + ... + 120173352.

It is an arithmetic number, because the mean of its divisors is an integer number (240346700).

Almost surely, 2^721040097 is an apocalyptic number.

It is an amenable number.

721040097 is a deficient number, since it is larger than the sum of its proper divisors (240346703).

721040097 is a wasteful number, since it uses less digits than its factorization.

721040097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240346702.

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 721040097 is about 26852.1897989717. The cubic root of 721040097 is about 896.7123245884.

Adding to 721040097 its sum of digits (30), we get a palindrome (721040127).

The spelling of 721040097 in words is "seven hundred twenty-one million, forty thousand, ninety-seven".