721421001 has 48 divisors (see below), whose sum is σ = 1239473664. Its totient is φ = 395770752.

The previous prime is 721420951. The next prime is 721421003. The reversal of 721421001 is 100124127.

It is not a de Polignac number, because 721421001 - 2⁹ = 721420489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (721421003) 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, 154635 + ... + 159231.

It is an arithmetic number, because the mean of its divisors is an integer number (25822368).

Almost surely, 2^721421001 is an apocalyptic number.

It is an amenable number.

721421001 is a deficient number, since it is larger than the sum of its proper divisors (518052663).

721421001 is a wasteful number, since it uses less digits than its factorization.

721421001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4710 (or 4707 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 721421001 is about 26859.2814684235. The cubic root of 721421001 is about 896.8701989262.

Adding to 721421001 its reverse (100124127), we get a palindrome (821545128).

The spelling of 721421001 in words is "seven hundred twenty-one million, four hundred twenty-one thousand, one".