1978661053 has 4 divisors (see below), whose sum is σ = 1981601788. Its totient is φ = 1975720320.

The previous prime is 1978661021. The next prime is 1978661063. The reversal of 1978661053 is 3501668791.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3501668791 = 1721 ⋅2034671.

It can be written as a sum of positive squares in 2 ways, for example, as 264452644 + 1714208409 = 16262^2 + 41403^2 .

It is a cyclic number.

It is not a de Polignac number, because 1978661053 - 2⁵ = 1978661021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1978660994 and 1978661012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978661063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1469358 + ... + 1470703.

It is an arithmetic number, because the mean of its divisors is an integer number (495400447).

Almost surely, 2^1978661053 is an apocalyptic number.

It is an amenable number.

1978661053 is a deficient number, since it is larger than the sum of its proper divisors (2940735).

1978661053 is an equidigital number, since it uses as much as digits as its factorization.

1978661053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2940734.

The product of its (nonzero) digits is 272160, while the sum is 46.

The square root of 1978661053 is about 44482.1430801170. The cubic root of 1978661053 is about 1255.4241203965.

The spelling of 1978661053 in words is "one billion, nine hundred seventy-eight million, six hundred sixty-one thousand, fifty-three".