1661953275 has 48 divisors (see below), whose sum is σ = 3213782400. Its totient is φ = 839717280.

The previous prime is 1661953247. The next prime is 1661953289. The reversal of 1661953275 is 5723591661.

1661953275 is a `hidden beast` number, since 1 + 6 + 619 + 5 + 3 + 27 + 5 = 666.

It is not a de Polignac number, because 1661953275 - 2⁷ = 1661953147 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 1661953275.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 51969 + ... + 77618.

It is an arithmetic number, because the mean of its divisors is an integer number (66953800).

Almost surely, 2^1661953275 is an apocalyptic number.

1661953275 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1661953275 is a deficient number, since it is larger than the sum of its proper divisors (1551829125).

1661953275 is a wasteful number, since it uses less digits than its factorization.

1661953275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129625 (or 129614 counting only the distinct ones).

The product of its digits is 340200, while the sum is 45.

The square root of 1661953275 is about 40767.0611523568. The cubic root of 1661953275 is about 1184.5123774854.

The spelling of 1661953275 in words is "one billion, six hundred sixty-one million, nine hundred fifty-three thousand, two hundred seventy-five".