1662121764 has 72 divisors (see below), whose sum is σ = 4335327360. Its totient is φ = 536657472.

The previous prime is 1662121723. The next prime is 1662121777. The reversal of 1662121764 is 4671212661.

1662121764 is a `hidden beast` number, since 1 + 6 + 621 + 21 + 7 + 6 + 4 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 145219 + ... + 156245.

It is an arithmetic number, because the mean of its divisors is an integer number (60212880).

Almost surely, 2^1662121764 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 1662121764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2167663680).

1662121764 is an abundant number, since it is smaller than the sum of its proper divisors (2673205596).

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

1662121764 is a wasteful number, since it uses less digits than its factorization.

1662121764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11169 (or 11164 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 1662121764 is about 40769.1275844848. The cubic root of 1662121764 is about 1184.5524047964.

The spelling of 1662121764 in words is "one billion, six hundred sixty-two million, one hundred twenty-one thousand, seven hundred sixty-four".