1978905743 has 4 divisors (see below), whose sum is σ = 2032389720. Its totient is φ = 1925421768.

The previous prime is 1978905703. The next prime is 1978905787. The reversal of 1978905743 is 3475098791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1978905743 - 2¹⁸ = 1978643599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978905703) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26741933 + ... + 26742006.

It is an arithmetic number, because the mean of its divisors is an integer number (508097430).

Almost surely, 2^1978905743 is an apocalyptic number.

1978905743 is a deficient number, since it is larger than the sum of its proper divisors (53483977).

1978905743 is an equidigital number, since it uses as much as digits as its factorization.

1978905743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53483976.

The product of its (nonzero) digits is 1905120, while the sum is 53.

The square root of 1978905743 is about 44484.8934246223. The cubic root of 1978905743 is about 1255.4758687014.

The spelling of 1978905743 in words is "one billion, nine hundred seventy-eight million, nine hundred five thousand, seven hundred forty-three".