1971989460 has 288 divisors, whose sum is σ = 7410154752. Its totient is φ = 414167040.

The previous prime is 1971989441. The next prime is 1971989471. The reversal of 1971989460 is 649891791.

1971989460 is a `hidden beast` number, since 1 + 97 + 1 + 98 + 9 + 460 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 1971989397 and 1971989406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 919990 + ... + 922130.

It is an arithmetic number, because the mean of its divisors is an integer number (25729704).

Almost surely, 2^1971989460 is an apocalyptic number.

1971989460 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 1971989460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3705077376).

1971989460 is an abundant number, since it is smaller than the sum of its proper divisors (5438165292).

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

1971989460 is a wasteful number, since it uses less digits than its factorization.

1971989460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2223 (or 2218 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 54.

The square root of 1971989460 is about 44407.0879477590. The cubic root of 1971989460 is about 1254.0115304603.

The spelling of 1971989460 in words is "one billion, nine hundred seventy-one million, nine hundred eighty-nine thousand, four hundred sixty".