1667287440 has 240 divisors, whose sum is σ = 6891725568. Its totient is φ = 351765504.

The previous prime is 1667287439. The next prime is 1667287469. The reversal of 1667287440 is 447827661.

1667287440 is a `hidden beast` number, since 1 + 66 + 72 + 87 + 440 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-3 number, since 3×1667287440³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 52797 + ... + 78243.

Almost surely, 2^1667287440 is an apocalyptic number.

1667287440 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 1667287440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3445862784).

1667287440 is an abundant number, since it is smaller than the sum of its proper divisors (5224438128).

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

1667287440 is a wasteful number, since it uses less digits than its factorization.

1667287440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25486 (or 25477 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 45.

The square root of 1667287440 is about 40832.4312281304. The cubic root of 1667287440 is about 1185.7782848589.

The spelling of 1667287440 in words is "one billion, six hundred sixty-seven million, two hundred eighty-seven thousand, four hundred forty".