1671543640 has 64 divisors (see below), whose sum is σ = 4099183200. Its totient is φ = 609733632.

The previous prime is 1671543617. The next prime is 1671543641. The reversal of 1671543640 is 463451761.

It is a self number, because there is not a number n which added to its sum of digits gives 1671543640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1671543641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23796 + ... + 62524.

Almost surely, 2^1671543640 is an apocalyptic number.

1671543640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1671543640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2049591600).

1671543640 is an abundant number, since it is smaller than the sum of its proper divisors (2427639560).

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

1671543640 is a wasteful number, since it uses less digits than its factorization.

1671543640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38836 (or 38832 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 1671543640 is about 40884.5158953851. The cubic root of 1671543640 is about 1186.7864335767.

The spelling of 1671543640 in words is "one billion, six hundred seventy-one million, five hundred forty-three thousand, six hundred forty".