671402781 has 48 divisors (see below), whose sum is σ = 1135420416. Its totient is φ = 374370048.

The previous prime is 671402773. The next prime is 671402813. The reversal of 671402781 is 187204176.

It is not a de Polignac number, because 671402781 - 2³ = 671402773 is a prime.

It is a super-2 number, since 2×671402781² = 901563388669067922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671442781) 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, 777556 + ... + 778418.

It is an arithmetic number, because the mean of its divisors is an integer number (23654592).

Almost surely, 2^671402781 is an apocalyptic number.

It is an amenable number.

671402781 is a deficient number, since it is larger than the sum of its proper divisors (464017635).

671402781 is a wasteful number, since it uses less digits than its factorization.

671402781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1162 (or 1159 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 671402781 is about 25911.4411216358. The cubic root of 671402781 is about 875.6442736871.

The spelling of 671402781 in words is "six hundred seventy-one million, four hundred two thousand, seven hundred eighty-one".