1664157600 has 648 divisors, whose sum is σ = 7033260780. Its totient is φ = 369008640.

The previous prime is 1664157563. The next prime is 1664157601. The reversal of 1664157600 is 67514661.

1664157600 is a `hidden beast` number, since 1 + 6 + 6 + 41 + 5 + 7 + 600 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 518199696 + 1145957904 = 22764^2 + 33852^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664157601) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 18698356 + ... + 18698444.

Almost surely, 2^1664157600 is an apocalyptic number.

1664157600 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 1664157600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3516630390).

1664157600 is an abundant number, since it is smaller than the sum of its proper divisors (5369103180).

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

1664157600 is a wasteful number, since it uses less digits than its factorization.

1664157600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 1664157600 is about 40794.0878069359. The cubic root of 1664157600 is about 1185.0358371900.

It can be divided in two parts, 16641 and 57600, that multiplied together give a square (958521600 = 30960²).

The spelling of 1664157600 in words is "one billion, six hundred sixty-four million, one hundred fifty-seven thousand, six hundred".