1661485216 has 12 divisors (see below), whose sum is σ = 3271049082. Its totient is φ = 830742592.

The previous prime is 1661485187. The next prime is 1661485237. The reversal of 1661485216 is 6125841661.

It can be written as a sum of positive squares in only one way, i.e., 1379379600 + 282105616 = 37140^2 + 16796^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25960675 + ... + 25960738.

Almost surely, 2^1661485216 is an apocalyptic number.

1661485216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1661485216 is a deficient number, since it is larger than the sum of its proper divisors (1609563866).

1661485216 is an equidigital number, since it uses as much as digits as its factorization.

1661485216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51921423 (or 51921415 counting only the distinct ones).

The product of its digits is 69120, while the sum is 40.

The square root of 1661485216 is about 40761.3200963855. The cubic root of 1661485216 is about 1184.4011682348.

The spelling of 1661485216 in words is "one billion, six hundred sixty-one million, four hundred eighty-five thousand, two hundred sixteen".