188121428 has 24 divisors (see below), whose sum is σ = 359696064. Its totient is φ = 85377600.

The previous prime is 188121391. The next prime is 188121443. The reversal of 188121428 is 824121881.

It is a happy number.

It is a super-4 number, since 4×188121428⁴ (a number of 34 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29048 + ... + 34928.

It is an arithmetic number, because the mean of its divisors is an integer number (14987336).

Almost surely, 2^188121428 is an apocalyptic number.

It is an amenable number.

188121428 is a deficient number, since it is larger than the sum of its proper divisors (171574636).

188121428 is a wasteful number, since it uses less digits than its factorization.

188121428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6623 (or 6621 counting only the distinct ones).

The product of its digits is 8192, while the sum is 35.

The square root of 188121428 is about 13715.7365095718. The cubic root of 188121428 is about 572.9887417622.

The spelling of 188121428 in words is "one hundred eighty-eight million, one hundred twenty-one thousand, four hundred twenty-eight".