1661055551598 has 32 divisors (see below), whose sum is σ = 3517781170176. Its totient is φ = 521078168448.

The previous prime is 1661055551537. The next prime is 1661055551611. The reversal of 1661055551598 is 8951555501661.

It is a Curzon number.

It is a congruent number.

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, 866865 + ... + 2018307.

It is an arithmetic number, because the mean of its divisors is an integer number (109930661568).

Almost surely, 2^{1661055551598} is an apocalyptic number.

1661055551598 is an abundant number, since it is smaller than the sum of its proper divisors (1856725618578).

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

1661055551598 is a wasteful number, since it uses less digits than its factorization.

1661055551598 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1165608.

The product of its (nonzero) digits is 8100000, while the sum is 57.

The spelling of 1661055551598 in words is "one trillion, six hundred sixty-one billion, fifty-five million, five hundred fifty-one thousand, five hundred ninety-eight".