1664900440 has 192 divisors, whose sum is σ = 4775824800. Its totient is φ = 518418432.

The previous prime is 1664900437. The next prime is 1664900443. The reversal of 1664900440 is 440094661.

It is an interprime number because it is at equal distance from previous prime (1664900437) and next prime (1664900443).

It is a super-2 number, since 2×1664900440² = 5543786950224387200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 1664900396 and 1664900405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664900443) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 965419 + ... + 967141.

Almost surely, 2^1664900440 is an apocalyptic number.

1664900440 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 1664900440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2387912400).

1664900440 is an abundant number, since it is smaller than the sum of its proper divisors (3110924360).

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

1664900440 is a wasteful number, since it uses less digits than its factorization.

1664900440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1794 (or 1783 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 1664900440 is about 40803.1915418390. The cubic root of 1664900440 is about 1185.2121348101.

The spelling of 1664900440 in words is "one billion, six hundred sixty-four million, nine hundred thousand, four hundred forty".