1671572621 has 2 divisors, whose sum is σ = 1671572622. Its totient is φ = 1671572620.

The previous prime is 1671572597. The next prime is 1671572627. The reversal of 1671572621 is 1262751761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 977250121 + 694322500 = 31261^2 + 26350^2 .

It is a cyclic number.

It is not a de Polignac number, because 1671572621 - 2³⁰ = 597830797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1671572627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 835786310 + 835786311.

It is an arithmetic number, because the mean of its divisors is an integer number (835786311).

Almost surely, 2^1671572621 is an apocalyptic number.

It is an amenable number.

1671572621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1671572621 is an equidigital number, since it uses as much as digits as its factorization.

1671572621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35280, while the sum is 38.

The square root of 1671572621 is about 40884.8703189823. The cubic root of 1671572621 is about 1186.7932923185.

The spelling of 1671572621 in words is "one billion, six hundred seventy-one million, five hundred seventy-two thousand, six hundred twenty-one".