1604636880 has 320 divisors, whose sum is σ = 6404161536. Its totient is φ = 322560000.

The previous prime is 1604636809. The next prime is 1604636881. The reversal of 1604636880 is 886364061.

It is a happy number.

It is a super-2 number, since 2×1604636880² = 5149719033312268800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1604636881) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 571480 + ... + 574280.

Almost surely, 2^1604636880 is an apocalyptic number.

1604636880 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 1604636880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3202080768).

1604636880 is an abundant number, since it is smaller than the sum of its proper divisors (4799524656).

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

1604636880 is a wasteful number, since it uses less digits than its factorization.

1604636880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2866 (or 2860 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 1604636880 is about 40057.9190672706. The cubic root of 1604636880 is about 1170.7358655230.

The spelling of 1604636880 in words is "one billion, six hundred four million, six hundred thirty-six thousand, eight hundred eighty".