2154778065972 has 192 divisors, whose sum is σ = 6509556264960. Its totient is φ = 603610869888.

The previous prime is 2154778065901. The next prime is 2154778065977. The reversal of 2154778065972 is 2795608774512.

2154778065972 is a `hidden beast` number, since 2 + 1 + 547 + 7 + 80 + 6 + 5 + 9 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2154778065977) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 59402713 + ... + 59438975.

It is an arithmetic number, because the mean of its divisors is an integer number (33903938880).

Almost surely, 2^{2154778065972} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2154778065972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3254778132480).

2154778065972 is an abundant number, since it is smaller than the sum of its proper divisors (4354778198988).

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

2154778065972 is a wasteful number, since it uses less digits than its factorization.

2154778065972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37819 (or 37811 counting only the distinct ones).

The product of its (nonzero) digits is 59270400, while the sum is 63.

The spelling of 2154778065972 in words is "two trillion, one hundred fifty-four billion, seven hundred seventy-eight million, sixty-five thousand, nine hundred seventy-two".