2778955680400 has 135 divisors (see below), whose sum is σ = 7093721531451. Its totient is φ = 1045981701120.

The previous prime is 2778955680379. The next prime is 2778955680407. The reversal of 2778955680400 is 40865598772.

The square root of 2778955680400 is 1667020.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 65002561936 + 2713953118464 = 254956^2 + 1647408^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2778955680407) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 566784349 + ... + 566789251.

Almost surely, 2^{2778955680400} is an apocalyptic number.

2778955680400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

2778955680400 is the 1667020-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2778955680400

2778955680400 is an abundant number, since it is smaller than the sum of its proper divisors (4314765851051).

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

2778955680400 is an frugal number, since it uses more digits than its factorization.

2778955680400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9858 (or 4927 counting only the distinct ones).

The product of its (nonzero) digits is 33868800, while the sum is 61.

The spelling of 2778955680400 in words is "two trillion, seven hundred seventy-eight billion, nine hundred fifty-five million, six hundred eighty thousand, four hundred".