1920193921 has 16 divisors (see below), whose sum is σ = 1997178768. Its totient is φ = 1844640000.

The previous prime is 1920193901. The next prime is 1920193943. The reversal of 1920193921 is 1293910291.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1431562896 + 488631025 = 37836^2 + 22105^2 .

It is a cyclic number.

It is not a de Polignac number, because 1920193921 - 2²⁹ = 1383323009 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1920193901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2619271 + ... + 2620003.

It is an arithmetic number, because the mean of its divisors is an integer number (124823673).

Almost surely, 2^1920193921 is an apocalyptic number.

It is an amenable number.

1920193921 is a deficient number, since it is larger than the sum of its proper divisors (76984847).

1920193921 is a wasteful number, since it uses less digits than its factorization.

1920193921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1572.

The product of its (nonzero) digits is 8748, while the sum is 37.

The square root of 1920193921 is about 43820.0173550856. The cubic root of 1920193921 is about 1242.9348452531.

The spelling of 1920193921 in words is "one billion, nine hundred twenty million, one hundred ninety-three thousand, nine hundred twenty-one".