1981597040 has 40 divisors (see below), whose sum is σ = 4613142240. Its totient is φ = 791618816.

The previous prime is 1981597021. The next prime is 1981597081. The reversal of 1981597040 is 407951891.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 1981596982 and 1981597000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48221 + ... + 79299.

It is an arithmetic number, because the mean of its divisors is an integer number (115328556).

Almost surely, 2^1981597040 is an apocalyptic number.

1981597040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1981597040 is an abundant number, since it is smaller than the sum of its proper divisors (2631545200).

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

1981597040 is a wasteful number, since it uses less digits than its factorization.

1981597040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31889 (or 31883 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 44.

The square root of 1981597040 is about 44515.1327078781. The cubic root of 1981597040 is about 1256.0447568131.

The spelling of 1981597040 in words is "one billion, nine hundred eighty-one million, five hundred ninety-seven thousand, forty".