1661071664 has 20 divisors (see below), whose sum is σ = 3678087504. Its totient is φ = 711887808.

The previous prime is 1661071651. The next prime is 1661071681. The reversal of 1661071664 is 4661701661.

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, 7415387 + ... + 7415610.

Almost surely, 2^1661071664 is an apocalyptic number.

1661071664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1661071664 is an abundant number, since it is smaller than the sum of its proper divisors (2017015840).

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

1661071664 is a wasteful number, since it uses less digits than its factorization.

1661071664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14831012 (or 14831006 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 1661071664 is about 40756.2469322189. The cubic root of 1661071664 is about 1184.3028922843.

The spelling of 1661071664 in words is "one billion, six hundred sixty-one million, seventy-one thousand, six hundred sixty-four".