1978404251040 has 864 divisors, whose sum is σ = 8188577639424. Its totient is φ = 449756375040.

The previous prime is 1978404251029. The next prime is 1978404251053. The reversal of 1978404251040 is 401524048791.

1978404251040 is a `hidden beast` number, since 1 + 97 + 8 + 4 + 0 + 4 + 2 + 510 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 363875202 + ... + 363880638.

It is an arithmetic number, because the mean of its divisors is an integer number (9477520416).

Almost surely, 2^{1978404251040} is an apocalyptic number.

1978404251040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1978404251040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4094288819712).

1978404251040 is an abundant number, since it is smaller than the sum of its proper divisors (6210173388384).

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

1978404251040 is a wasteful number, since it uses less digits than its factorization.

1978404251040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5672 (or 5645 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The spelling of 1978404251040 in words is "one trillion, nine hundred seventy-eight billion, four hundred four million, two hundred fifty-one thousand, forty".