1640450540 has 24 divisors (see below), whose sum is σ = 3563738640. Its totient is φ = 633553088.

The previous prime is 1640450507. The next prime is 1640450593. The reversal of 1640450540 is 450540461.

It is a Harshad number since it is a multiple of its sum of digits (29).

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, 1413602 + ... + 1414761.

It is an arithmetic number, because the mean of its divisors is an integer number (148489110).

Almost surely, 2^1640450540 is an apocalyptic number.

1640450540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1640450540 is an abundant number, since it is smaller than the sum of its proper divisors (1923288100).

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

1640450540 is a wasteful number, since it uses less digits than its factorization.

1640450540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2828401 (or 2828399 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 1640450540 is about 40502.4757267997. The cubic root of 1640450540 is about 1179.3816879392.

The spelling of 1640450540 in words is "one billion, six hundred forty million, four hundred fifty thousand, five hundred forty".