1928377021 has 4 divisors (see below), whose sum is σ = 1947099232. Its totient is φ = 1909654812.

The previous prime is 1928377007. The next prime is 1928377039. The reversal of 1928377021 is 1207738291.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1928377021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1928377001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9360951 + ... + 9361156.

It is an arithmetic number, because the mean of its divisors is an integer number (486774808).

Almost surely, 2^1928377021 is an apocalyptic number.

It is an amenable number.

1928377021 is a deficient number, since it is larger than the sum of its proper divisors (18722211).

1928377021 is a wasteful number, since it uses less digits than its factorization.

1928377021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18722210.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 1928377021 is about 43913.2897993307. The cubic root of 1928377021 is about 1244.6979737577.

The spelling of 1928377021 in words is "one billion, nine hundred twenty-eight million, three hundred seventy-seven thousand, twenty-one".