1628672778 has 32 divisors (see below), whose sum is σ = 3668860800. Its totient is φ = 535452768.

The previous prime is 1628672719. The next prime is 1628672779. The reversal of 1628672778 is 8772768261.

It is a happy number.

1628672778 is a `hidden beast` number, since 1 + 628 + 6 + 7 + 2 + 7 + 7 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (1628672779) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 202638 + ... + 210521.

It is an arithmetic number, because the mean of its divisors is an integer number (114651900).

Almost surely, 2^1628672778 is an apocalyptic number.

1628672778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1628672778 is an abundant number, since it is smaller than the sum of its proper divisors (2040188022).

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

1628672778 is a wasteful number, since it uses less digits than its factorization.

1628672778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413243 (or 413237 counting only the distinct ones).

The product of its digits is 3161088, while the sum is 54.

The square root of 1628672778 is about 40356.8182343455. The cubic root of 1628672778 is about 1176.5524138339.

The spelling of 1628672778 in words is "one billion, six hundred twenty-eight million, six hundred seventy-two thousand, seven hundred seventy-eight".