721220156 has 12 divisors (see below), whose sum is σ = 1268676192. Its totient is φ = 358741248.

The previous prime is 721220153. The next prime is 721220161. The reversal of 721220156 is 651022127.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721220153) 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, 466340 + ... + 467883.

It is an arithmetic number, because the mean of its divisors is an integer number (105723016).

Almost surely, 2^721220156 is an apocalyptic number.

It is an amenable number.

721220156 is a deficient number, since it is larger than the sum of its proper divisors (547456036).

721220156 is a wasteful number, since it uses less digits than its factorization.

721220156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 934420 (or 934418 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 721220156 is about 26855.5423702445. The cubic root of 721220156 is about 896.7869610693.

The spelling of 721220156 in words is "seven hundred twenty-one million, two hundred twenty thousand, one hundred fifty-six".