1581643040 has 48 divisors (see below), whose sum is σ = 3739079232. Its totient is φ = 632242944.

The previous prime is 1581643027. The next prime is 1581643051. The reversal of 1581643040 is 403461851.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 1581642988 and 1581643006.

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, 392717 + ... + 396723.

It is an arithmetic number, because the mean of its divisors is an integer number (77897484).

Almost surely, 2^1581643040 is an apocalyptic number.

1581643040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1581643040 is an abundant number, since it is smaller than the sum of its proper divisors (2157436192).

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

1581643040 is a wasteful number, since it uses less digits than its factorization.

1581643040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6489 (or 6481 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 1581643040 is about 39769.8760370208. The cubic root of 1581643040 is about 1165.1168726039.

The spelling of 1581643040 in words is "one billion, five hundred eighty-one million, six hundred forty-three thousand, forty".