1671020521 has 2 divisors, whose sum is σ = 1671020522. Its totient is φ = 1671020520.

The previous prime is 1671020509. The next prime is 1671020539. The reversal of 1671020521 is 1250201761.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 956046400 + 714974121 = 30920^2 + 26739^2 .

It is a cyclic number.

It is not a de Polignac number, because 1671020521 - 2⁵ = 1671020489 is a prime.

It is a super-2 number, since 2×1671020521² = 5584619163206222882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1671020581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 835510260 + 835510261.

It is an arithmetic number, because the mean of its divisors is an integer number (835510261).

Almost surely, 2^1671020521 is an apocalyptic number.

It is an amenable number.

1671020521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1671020521 is an equidigital number, since it uses as much as digits as its factorization.

1671020521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 1671020521 is about 40878.1178749707. The cubic root of 1671020521 is about 1186.6626168257.

The spelling of 1671020521 in words is "one billion, six hundred seventy-one million, twenty thousand, five hundred twenty-one".