70001721 has 12 divisors (see below), whose sum is σ = 103465648. Its totient is φ = 45582264.

The previous prime is 70001683. The next prime is 70001741. The reversal of 70001721 is 12710007.

It is not a de Polignac number, because 70001721 - 2⁷ = 70001593 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 70001694 and 70001703.

It is not an unprimeable number, because it can be changed into a prime (70001741) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 90055 + ... + 90828.

Almost surely, 2^70001721 is an apocalyptic number.

It is an amenable number.

70001721 is a deficient number, since it is larger than the sum of its proper divisors (33463927).

70001721 is a wasteful number, since it uses less digits than its factorization.

70001721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180932 (or 180929 counting only the distinct ones).

The product of its (nonzero) digits is 98, while the sum is 18.

The square root of 70001721 is about 8366.7031141304. The cubic root of 70001721 is about 412.1319074446.

Adding to 70001721 its reverse (12710007), we get a palindrome (82711728).

The spelling of 70001721 in words is "seventy million, one thousand, seven hundred twenty-one".