1661455461200 has 60 divisors (see below), whose sum is σ = 3992115528060. Its totient is φ = 664504135680.

The previous prime is 1661455461163. The next prime is 1661455461203. The reversal of 1661455461200 is 21645541661.

It can be written as a sum of positive squares in 6 ways, for example, as 3067830544 + 1658387630656 = 55388^2 + 1287784^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661455461203) 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, 3228032 + ... + 3707168.

It is an arithmetic number, because the mean of its divisors is an integer number (66535258801).

Almost surely, 2^{1661455461200} is an apocalyptic number.

1661455461200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661455461200 is an abundant number, since it is smaller than the sum of its proper divisors (2330660066860).

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

1661455461200 is a wasteful number, since it uses less digits than its factorization.

1661455461200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487824 (or 487813 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 41.

The spelling of 1661455461200 in words is "one trillion, six hundred sixty-one billion, four hundred fifty-five million, four hundred sixty-one thousand, two hundred".