1611665216 has 56 divisors (see below), whose sum is σ = 3659038656. Its totient is φ = 689955840.

The previous prime is 1611665213. The next prime is 1611665219. The reversal of 1611665216 is 6125661161.

It is an interprime number because it is at equal distance from previous prime (1611665213) and next prime (1611665219).

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1611665213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 638036 + ... + 640556.

It is an arithmetic number, because the mean of its divisors is an integer number (65339976).

Almost surely, 2^1611665216 is an apocalyptic number.

1611665216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1611665216 is an abundant number, since it is smaller than the sum of its proper divisors (2047373440).

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

1611665216 is a wasteful number, since it uses less digits than its factorization.

1611665216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3967 (or 3957 counting only the distinct ones).

The product of its digits is 12960, while the sum is 35.

The square root of 1611665216 is about 40145.5503885549. The cubic root of 1611665216 is about 1172.4426568186.

The spelling of 1611665216 in words is "one billion, six hundred eleven million, six hundred sixty-five thousand, two hundred sixteen".