1921238772 has 12 divisors (see below), whose sum is σ = 4482890496. Its totient is φ = 640412920.

The previous prime is 1921238749. The next prime is 1921238773. The reversal of 1921238772 is 2778321291.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921238773) 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, 80051604 + ... + 80051627.

It is an arithmetic number, because the mean of its divisors is an integer number (373574208).

Almost surely, 2^1921238772 is an apocalyptic number.

1921238772 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1921238772 is an abundant number, since it is smaller than the sum of its proper divisors (2561651724).

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

1921238772 is a wasteful number, since it uses less digits than its factorization.

1921238772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160103238 (or 160103236 counting only the distinct ones).

The product of its digits is 84672, while the sum is 42.

The square root of 1921238772 is about 43831.9378079500. The cubic root of 1921238772 is about 1243.1602471806.

The spelling of 1921238772 in words is "one billion, nine hundred twenty-one million, two hundred thirty-eight thousand, seven hundred seventy-two".