1661983572 has 12 divisors (see below), whose sum is σ = 3877961696. Its totient is φ = 553994520.

The previous prime is 1661983571. The next prime is 1661983573. The reversal of 1661983572 is 2753891661.

It is an interprime number because it is at equal distance from previous prime (1661983571) and next prime (1661983573).

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661983571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69249304 + ... + 69249327.

Almost surely, 2^1661983572 is an apocalyptic number.

1661983572 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1661983572 is an abundant number, since it is smaller than the sum of its proper divisors (2215978124).

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

1661983572 is a wasteful number, since it uses less digits than its factorization.

1661983572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138498638 (or 138498636 counting only the distinct ones).

The product of its digits is 544320, while the sum is 48.

The square root of 1661983572 is about 40767.4327374192. The cubic root of 1661983572 is about 1184.5195752316.

The spelling of 1661983572 in words is "one billion, six hundred sixty-one million, nine hundred eighty-three thousand, five hundred seventy-two".