1427681621 has 2 divisors, whose sum is σ = 1427681622. Its totient is φ = 1427681620.

The previous prime is 1427681597. The next prime is 1427681639. The reversal of 1427681621 is 1261867241.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 747202225 + 680479396 = 27335^2 + 26086^2 .

It is a cyclic number.

It is not a de Polignac number, because 1427681621 - 2¹⁴ = 1427665237 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1427681681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 713840810 + 713840811.

It is an arithmetic number, because the mean of its divisors is an integer number (713840811).

Almost surely, 2^1427681621 is an apocalyptic number.

It is an amenable number.

1427681621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1427681621 is an equidigital number, since it uses as much as digits as its factorization.

1427681621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 38.

The square root of 1427681621 is about 37784.6744196639. The cubic root of 1427681621 is about 1126.0139983032.

The spelling of 1427681621 in words is "one billion, four hundred twenty-seven million, six hundred eighty-one thousand, six hundred twenty-one".