1640546400 has 144 divisors (see below), whose sum is σ = 5354282304. Its totient is φ = 436308480.

The previous prime is 1640546387. The next prime is 1640546423. The reversal of 1640546400 is 46450461.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1254547 + ... + 1255853.

It is an arithmetic number, because the mean of its divisors is an integer number (37182516).

Almost surely, 2^1640546400 is an apocalyptic number.

1640546400 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 1640546400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2677141152).

1640546400 is an abundant number, since it is smaller than the sum of its proper divisors (3713735904).

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

1640546400 is a wasteful number, since it uses less digits than its factorization.

1640546400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1853 (or 1840 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 1640546400 is about 40503.6590939634. The cubic root of 1640546400 is about 1179.4046599468.

Adding to 1640546400 its reverse (46450461), we get a palindrome (1686996861).

The spelling of 1640546400 in words is "one billion, six hundred forty million, five hundred forty-six thousand, four hundred".