2101778628 has 12 divisors (see below), whose sum is σ = 4904150160. Its totient is φ = 700592872.

The previous prime is 2101778603. The next prime is 2101778669. The reversal of 2101778628 is 8268771012.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×2101778628² = 8834946802235124768, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2101778628.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87574098 + ... + 87574121.

It is an arithmetic number, because the mean of its divisors is an integer number (408679180).

Almost surely, 2^2101778628 is an apocalyptic number.

It is an amenable number.

2101778628 is an abundant number, since it is smaller than the sum of its proper divisors (2802371532).

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

2101778628 is a wasteful number, since it uses less digits than its factorization.

2101778628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175148226 (or 175148224 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 42.

The square root of 2101778628 is about 45845.1592646377. The cubic root of 2101778628 is about 1280.9405985151.

The spelling of 2101778628 in words is "two billion, one hundred one million, seven hundred seventy-eight thousand, six hundred twenty-eight".