1611403661 has 12 divisors (see below), whose sum is σ = 1973148480. Its totient is φ = 1308507480.

The previous prime is 1611403657. The next prime is 1611403681. The reversal of 1611403661 is 1663041161.

It is not a de Polignac number, because 1611403661 - 2² = 1611403657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1611403631) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 864485 + ... + 866346.

It is an arithmetic number, because the mean of its divisors is an integer number (164429040).

Almost surely, 2^1611403661 is an apocalyptic number.

It is an amenable number.

1611403661 is a deficient number, since it is larger than the sum of its proper divisors (361744819).

1611403661 is a wasteful number, since it uses less digits than its factorization.

1611403661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1730864 (or 1730857 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 1611403661 is about 40142.2926724421. The cubic root of 1611403661 is about 1172.3792286685.

The spelling of 1611403661 in words is "one billion, six hundred eleven million, four hundred three thousand, six hundred sixty-one".