1921520171 has 2 divisors, whose sum is σ = 1921520172. Its totient is φ = 1921520170.

The previous prime is 1921520147. The next prime is 1921520189. The reversal of 1921520171 is 1710251291.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1921520171 is a prime.

It is not a weakly prime, because it can be changed into another prime (1921520101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960760085 + 960760086.

It is an arithmetic number, because the mean of its divisors is an integer number (960760086).

Almost surely, 2^1921520171 is an apocalyptic number.

1921520171 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921520171 is an equidigital number, since it uses as much as digits as its factorization.

1921520171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 29.

The square root of 1921520171 is about 43835.1476671403. The cubic root of 1921520171 is about 1243.2209384002.

The spelling of 1921520171 in words is "one billion, nine hundred twenty-one million, five hundred twenty thousand, one hundred seventy-one".