1920163921 has 32 divisors (see below), whose sum is σ = 2285942400. Its totient is φ = 1596672000.

The previous prime is 1920163907. The next prime is 1920163943. The reversal of 1920163921 is 1293610291.

It is a cyclic number.

It is not a de Polignac number, because 1920163921 - 2²⁵ = 1886609489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1920161921) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 477921 + ... + 481921.

It is an arithmetic number, because the mean of its divisors is an integer number (71435700).

Almost surely, 2^1920163921 is an apocalyptic number.

It is an amenable number.

1920163921 is a deficient number, since it is larger than the sum of its proper divisors (365778479).

1920163921 is a wasteful number, since it uses less digits than its factorization.

1920163921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4129.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 1920163921 is about 43819.6750444364. The cubic root of 1920163921 is about 1242.9283722541.

The spelling of 1920163921 in words is "one billion, nine hundred twenty million, one hundred sixty-three thousand, nine hundred twenty-one".