1864505664 has 252 divisors, whose sum is σ = 6420355968. Its totient is φ = 515289600.

The previous prime is 1864505659. The next prime is 1864505693. The reversal of 1864505664 is 4665054681.

1864505664 is a `hidden beast` number, since 1 + 86 + 4 + 5 + 0 + 566 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (252).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 873879 + ... + 876009.

Almost surely, 2^1864505664 is an apocalyptic number.

1864505664 is a gapful number since it is divisible by the number (14) 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 1864505664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3210177984).

1864505664 is an abundant number, since it is smaller than the sum of its proper divisors (4555850304).

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

1864505664 is a wasteful number, since it uses less digits than its factorization.

1864505664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2194 (or 2174 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The square root of 1864505664 is about 43179.9220008559. The cubic root of 1864505664 is about 1230.8011754337.

It can be divided in two parts, 1864 and 505664, that added together give a triangular number (507528 = T₁₀₀₇).

The spelling of 1864505664 in words is "one billion, eight hundred sixty-four million, five hundred five thousand, six hundred sixty-four".