1671261636 has 72 divisors (see below), whose sum is σ = 4509588384. Its totient is φ = 476099840.

The previous prime is 1671261589. The next prime is 1671261637. The reversal of 1671261636 is 6361621761.

It is a junction number, because it is equal to n+sod(n) for n = 1671261594 and 1671261603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1671261637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1936141 + ... + 1937003.

It is an arithmetic number, because the mean of its divisors is an integer number (62633172).

Almost surely, 2^1671261636 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1671261636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2254794192).

1671261636 is an abundant number, since it is smaller than the sum of its proper divisors (2838326748).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1671261636 is a wasteful number, since it uses less digits than its factorization.

1671261636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1761 (or 896 counting only the distinct ones).

The product of its digits is 54432, while the sum is 39.

The square root of 1671261636 is about 40881.0669625928. The cubic root of 1671261636 is about 1186.7196894135.

The spelling of 1671261636 in words is "one billion, six hundred seventy-one million, two hundred sixty-one thousand, six hundred thirty-six".