1540021680 has 80 divisors (see below), whose sum is σ = 5304526560. Its totient is φ = 410671872.

The previous prime is 1540021663. The next prime is 1540021709. The reversal of 1540021680 is 861200451.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 354327 + ... + 358646.

It is an arithmetic number, because the mean of its divisors is an integer number (66306582).

Almost surely, 2^1540021680 is an apocalyptic number.

1540021680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1540021680 is an abundant number, since it is smaller than the sum of its proper divisors (3764504880).

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

1540021680 is a wasteful number, since it uses less digits than its factorization.

1540021680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 712995 (or 712983 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 1540021680 is about 39243.1099685028. The cubic root of 1540021680 is about 1154.8057693292.

The spelling of 1540021680 in words is "one billion, five hundred forty million, twenty-one thousand, six hundred eighty".