1878877661 has 4 divisors (see below), whose sum is σ = 1879341024. Its totient is φ = 1878414300.

The previous prime is 1878877601. The next prime is 1878877699. The reversal of 1878877661 is 1667788781.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1878877661 - 2¹⁸ = 1878615517 is a prime.

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 1878877661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1878877601) 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, 225545 + ... + 233726.

It is an arithmetic number, because the mean of its divisors is an integer number (469835256).

Almost surely, 2^1878877661 is an apocalyptic number.

It is an amenable number.

1878877661 is a deficient number, since it is larger than the sum of its proper divisors (463363).

1878877661 is an equidigital number, since it uses as much as digits as its factorization.

1878877661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463362.

The product of its digits is 6322176, while the sum is 59.

The square root of 1878877661 is about 43346.0224357437. The cubic root of 1878877661 is about 1233.9555082302.

The spelling of 1878877661 in words is "one billion, eight hundred seventy-eight million, eight hundred seventy-seven thousand, six hundred sixty-one".