1978990741728 has 288 divisors, whose sum is σ = 7556147569152. Its totient is φ = 474483225600.

The previous prime is 1978990741727. The next prime is 1978990741729. The reversal of 1978990741728 is 8271470998791.

It is an interprime number because it is at equal distance from previous prime (1978990741727) and next prime (1978990741729).

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978990741723) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3144028 + ... + 3720603.

It is an arithmetic number, because the mean of its divisors is an integer number (26236623504).

Almost surely, 2^{1978990741728} is an apocalyptic number.

1978990741728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1978990741728 is an abundant number, since it is smaller than the sum of its proper divisors (5577156827424).

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

1978990741728 is a wasteful number, since it uses less digits than its factorization.

1978990741728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6864678 (or 6864667 counting only the distinct ones).

The product of its (nonzero) digits is 128024064, while the sum is 72.

The spelling of 1978990741728 in words is "one trillion, nine hundred seventy-eight billion, nine hundred ninety million, seven hundred forty-one thousand, seven hundred twenty-eight".