1661605661612 has 48 divisors (see below), whose sum is σ = 3142978917120. Its totient is φ = 764082071808.

The previous prime is 1661605661593. The next prime is 1661605661641. The reversal of 1661605661612 is 2161665061661.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71643314 + ... + 71666502.

It is an arithmetic number, because the mean of its divisors is an integer number (65478727440).

Almost surely, 2^{1661605661612} is an apocalyptic number.

It is an amenable number.

1661605661612 is a deficient number, since it is larger than the sum of its proper divisors (1481373255508).

1661605661612 is a wasteful number, since it uses less digits than its factorization.

1661605661612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28202 (or 28200 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 47.

The spelling of 1661605661612 in words is "one trillion, six hundred sixty-one billion, six hundred five million, six hundred sixty-one thousand, six hundred twelve".