721546781251 has 8 divisors (see below), whose sum is σ = 744861522944. Its totient is φ = 698234479560.

The previous prime is 721546781243. The next prime is 721546781257. The reversal of 721546781251 is 152187645127.

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

It is a cyclic number.

It is not a de Polignac number, because 721546781251 - 2³ = 721546781243 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721546781195 and 721546781204.

It is not an unprimeable number, because it can be changed into a prime (721546781257) 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, 706 + ... + 1201288.

It is an arithmetic number, because the mean of its divisors is an integer number (93107690368).

Almost surely, 2^721546781251 is an apocalyptic number.

721546781251 is a deficient number, since it is larger than the sum of its proper divisors (23314741693).

721546781251 is a wasteful number, since it uses less digits than its factorization.

721546781251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1220001.

The product of its digits is 940800, while the sum is 49.

The spelling of 721546781251 in words is "seven hundred twenty-one billion, five hundred forty-six million, seven hundred eighty-one thousand, two hundred fifty-one".