671721401 has 8 divisors (see below), whose sum is σ = 730416960. Its totient is φ = 614029392.

The previous prime is 671721397. The next prime is 671721419. The reversal of 671721401 is 104127176.

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 671721401 - 2² = 671721397 is a prime.

It is a super-2 number, since 2×671721401² = 902419281122805602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (671721451) 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, 249491 + ... + 252168.

It is an arithmetic number, because the mean of its divisors is an integer number (91302120).

Almost surely, 2^671721401 is an apocalyptic number.

It is an amenable number.

671721401 is a deficient number, since it is larger than the sum of its proper divisors (58695559).

671721401 is a wasteful number, since it uses less digits than its factorization.

671721401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501775.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 671721401 is about 25917.5886416927. The cubic root of 671721401 is about 875.7827666377.

Adding to 671721401 its reverse (104127176), we get a palindrome (775848577).

The spelling of 671721401 in words is "six hundred seventy-one million, seven hundred twenty-one thousand, four hundred one".