1947191988 has 72 divisors (see below), whose sum is σ = 5293536192. Its totient is φ = 555467136.

The previous prime is 1947191957. The next prime is 1947192011. The reversal of 1947191988 is 8891917491.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 434656 + ... + 439112.

It is an arithmetic number, because the mean of its divisors is an integer number (73521336).

Almost surely, 2^1947191988 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 1947191988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2646768096).

1947191988 is an abundant number, since it is smaller than the sum of its proper divisors (3346344204).

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

1947191988 is a wasteful number, since it uses less digits than its factorization.

1947191988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5221 (or 5212 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 57.

The square root of 1947191988 is about 44126.9984023387. The cubic root of 1947191988 is about 1248.7330069902.

The spelling of 1947191988 in words is "one billion, nine hundred forty-seven million, one hundred ninety-one thousand, nine hundred eighty-eight".