1661377600 has 63 divisors (see below), whose sum is σ = 4092042997. Its totient is φ = 663898880.

The previous prime is 1661377579. The next prime is 1661377621. The reversal of 1661377600 is 67731661.

The square root of 1661377600 is 40760.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (1661377579) and next prime (1661377621).

It can be written as a sum of positive squares in only one way, i.e., 598095936 + 1063281664 = 24456^2 + 32608^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1661377600.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1629891 + ... + 1630909.

Almost surely, 2^1661377600 is an apocalyptic number.

1661377600 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1661377600 is the 40760-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661377600

1661377600 is an abundant number, since it is smaller than the sum of its proper divisors (2430665397).

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

1661377600 is an frugal number, since it uses more digits than its factorization.

1661377600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2060 (or 1026 counting only the distinct ones).

The product of its (nonzero) digits is 31752, while the sum is 37.

The cubic root of 1661377600 is about 1184.3755960807.

The spelling of 1661377600 in words is "one billion, six hundred sixty-one million, three hundred seventy-seven thousand, six hundred".