721205961 has 48 divisors (see below), whose sum is σ = 1161530496. Its totient is φ = 396555264.

The previous prime is 721205941. The next prime is 721205983. The reversal of 721205961 is 169502127.

It is not a de Polignac number, because 721205961 - 2⁹ = 721205449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (721205941) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 526900 + ... + 528266.

It is an arithmetic number, because the mean of its divisors is an integer number (24198552).

Almost surely, 2^721205961 is an apocalyptic number.

It is an amenable number.

721205961 is a deficient number, since it is larger than the sum of its proper divisors (440324535).

721205961 is a wasteful number, since it uses less digits than its factorization.

721205961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1518 (or 1511 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 721205961 is about 26855.2780845777. The cubic root of 721205961 is about 896.7810775332.

The spelling of 721205961 in words is "seven hundred twenty-one million, two hundred five thousand, nine hundred sixty-one".