1978077738 has 160 divisors (see below), whose sum is σ = 5239672704. Its totient is φ = 485941248.

The previous prime is 1978077691. The next prime is 1978077743. The reversal of 1978077738 is 8377708791.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 20392506 + ... + 20392602.

Almost surely, 2^1978077738 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1978077738, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2619836352).

1978077738 is an abundant number, since it is smaller than the sum of its proper divisors (3261594966).

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

1978077738 is an equidigital number, since it uses as much as digits as its factorization.

1978077738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 4148928, while the sum is 57.

The square root of 1978077738 is about 44475.5858646067. The cubic root of 1978077738 is about 1255.3007407179.

The spelling of 1978077738 in words is "one billion, nine hundred seventy-eight million, seventy-seven thousand, seven hundred thirty-eight".