671987649 has 8 divisors (see below), whose sum is σ = 943140640. Its totient is φ = 424413216.

The previous prime is 671987629. The next prime is 671987669. The reversal of 671987649 is 946789176.

It is an interprime number because it is at equal distance from previous prime (671987629) and next prime (671987669).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 671987649 - 2¹³ = 671979457 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 11789257 = 671987649 / (6 + 7 + 1 + 9 + 8 + 7 + 6 + 4 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671987629) 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, 5894572 + ... + 5894685.

It is an arithmetic number, because the mean of its divisors is an integer number (117892580).

Almost surely, 2^671987649 is an apocalyptic number.

It is an amenable number.

671987649 is a deficient number, since it is larger than the sum of its proper divisors (271152991).

671987649 is a wasteful number, since it uses less digits than its factorization.

671987649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11789279.

The product of its digits is 4572288, while the sum is 57.

The square root of 671987649 is about 25922.7245674524. The cubic root of 671987649 is about 875.8984617303.

It can be divided in two parts, 67198 and 7649, that added together give a palindrome (74847).

The spelling of 671987649 in words is "six hundred seventy-one million, nine hundred eighty-seven thousand, six hundred forty-nine".