2121920428 has 24 divisors (see below), whose sum is σ = 3740117472. Its totient is φ = 1053333504.

The previous prime is 2121920417. The next prime is 2121920429. The reversal of 2121920428 is 8240291212.

It is a self number, because there is not a number n which added to its sum of digits gives 2121920428.

It is not an unprimeable number, because it can be changed into a prime (2121920429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 612076 + ... + 615532.

It is an arithmetic number, because the mean of its divisors is an integer number (155838228).

Almost surely, 2^2121920428 is an apocalyptic number.

It is an amenable number.

2121920428 is a deficient number, since it is larger than the sum of its proper divisors (1618197044).

2121920428 is a wasteful number, since it uses less digits than its factorization.

2121920428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4521 (or 4519 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 2121920428 is about 46064.3075276292. The cubic root of 2121920428 is about 1285.0194404241.

The spelling of 2121920428 in words is "two billion, one hundred twenty-one million, nine hundred twenty thousand, four hundred twenty-eight".