2154621797 has 2 divisors, whose sum is σ = 2154621798. Its totient is φ = 2154621796.

The previous prime is 2154621751. The next prime is 2154621839. The reversal of 2154621797 is 7971264512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2021311681 + 133310116 = 44959^2 + 11546^2 .

It is a cyclic number.

It is not a de Polignac number, because 2154621797 - 2⁸ = 2154621541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2154621097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077310898 + 1077310899.

It is an arithmetic number, because the mean of its divisors is an integer number (1077310899).

Almost surely, 2^2154621797 is an apocalyptic number.

It is an amenable number.

2154621797 is a deficient number, since it is larger than the sum of its proper divisors (1).

2154621797 is an equidigital number, since it uses as much as digits as its factorization.

2154621797 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 211680, while the sum is 44.

The square root of 2154621797 is about 46417.9038410827. The cubic root of 2154621797 is about 1291.5870531594.

The spelling of 2154621797 in words is "two billion, one hundred fifty-four million, six hundred twenty-one thousand, seven hundred ninety-seven".