1543421664 has 72 divisors (see below), whose sum is σ = 4400487000. Its totient is φ = 513139968.

The previous prime is 1543421641. The next prime is 1543421669. The reversal of 1543421664 is 4661243451.

1543421664 is a `hidden beast` number, since 1 + 5 + 434 + 216 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

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 (1543421669) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 107587 + ... + 121085.

It is an arithmetic number, because the mean of its divisors is an integer number (61117875).

Almost surely, 2^1543421664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1543421664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2200243500).

1543421664 is an abundant number, since it is smaller than the sum of its proper divisors (2857065336).

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

1543421664 is a wasteful number, since it uses less digits than its factorization.

1543421664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13912 (or 13901 counting only the distinct ones).

The product of its digits is 69120, while the sum is 36.

The square root of 1543421664 is about 39286.4055876839. The cubic root of 1543421664 is about 1155.6549857791.

The spelling of 1543421664 in words is "one billion, five hundred forty-three million, four hundred twenty-one thousand, six hundred sixty-four".