1921428144 has 60 divisors (see below), whose sum is σ = 5457616216. Its totient is φ = 630913536.

The previous prime is 1921428137. The next prime is 1921428169. The reversal of 1921428144 is 4418241291.

1921428144 is a `hidden beast` number, since 1 + 92 + 1 + 428 + 144 = 666.

It is a super-2 number, since 2×1921428144² = 7383772225110569472, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 1921428099 and 1921428108.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 89929 + ... + 109224.

Almost surely, 2^1921428144 is an apocalyptic number.

It is an amenable number.

1921428144 is an abundant number, since it is smaller than the sum of its proper divisors (3536188072).

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

1921428144 is a wasteful number, since it uses less digits than its factorization.

1921428144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199234 (or 199225 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 1921428144 is about 43834.0979603778. The cubic root of 1921428144 is about 1243.2010909687.

The spelling of 1921428144 in words is "one billion, nine hundred twenty-one million, four hundred twenty-eight thousand, one hundred forty-four".