721400113455221 has 8 divisors (see below), whose sum is σ = 762684560311200. Its totient is φ = 680447268582480.

The previous prime is 721400113455181. The next prime is 721400113455247. The reversal of 721400113455221 is 122554311004127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 721400113455221 - 2¹⁸ = 721400113193077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721400113458221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82900491335 + ... + 82900500036.

It is an arithmetic number, because the mean of its divisors is an integer number (95335570038900).

Almost surely, 2^{721400113455221} is an apocalyptic number.

It is an amenable number.

721400113455221 is a deficient number, since it is larger than the sum of its proper divisors (41284446855979).

721400113455221 is a wasteful number, since it uses less digits than its factorization.

721400113455221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165800991619.

The product of its (nonzero) digits is 67200, while the sum is 38.

Adding to 721400113455221 its reverse (122554311004127), we get a palindrome (843954424459348).

The spelling of 721400113455221 in words is "seven hundred twenty-one trillion, four hundred billion, one hundred thirteen million, four hundred fifty-five thousand, two hundred twenty-one".