1671561238 has 4 divisors (see below), whose sum is σ = 2507341860. Its totient is φ = 835780618.

The previous prime is 1671561197. The next prime is 1671561239. The reversal of 1671561238 is 8321651761.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1671561238.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1671561239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 417890308 + ... + 417890311.

It is an arithmetic number, because the mean of its divisors is an integer number (626835465).

Almost surely, 2^1671561238 is an apocalyptic number.

1671561238 is a deficient number, since it is larger than the sum of its proper divisors (835780622).

1671561238 is an equidigital number, since it uses as much as digits as its factorization.

1671561238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 835780621.

The product of its digits is 60480, while the sum is 40.

The square root of 1671561238 is about 40884.7311107704. The cubic root of 1671561238 is about 1186.7905983886.

The spelling of 1671561238 in words is "one billion, six hundred seventy-one million, five hundred sixty-one thousand, two hundred thirty-eight".