1661989268 has 12 divisors (see below), whose sum is σ = 2910432000. Its totient is φ = 830437272.

The previous prime is 1661989249. The next prime is 1661989291. The reversal of 1661989268 is 8629891661.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132596 + ... + 144587.

It is an arithmetic number, because the mean of its divisors is an integer number (242536000).

Almost surely, 2^1661989268 is an apocalyptic number.

It is an amenable number.

1661989268 is a deficient number, since it is larger than the sum of its proper divisors (1248442732).

1661989268 is a wasteful number, since it uses less digits than its factorization.

1661989268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278686 (or 278684 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 56.

The square root of 1661989268 is about 40767.5025970441. The cubic root of 1661989268 is about 1184.5209284370.

The spelling of 1661989268 in words is "one billion, six hundred sixty-one million, nine hundred eighty-nine thousand, two hundred sixty-eight".