2025021781 has 2 divisors, whose sum is σ = 2025021782. Its totient is φ = 2025021780.

The previous prime is 2025021763. The next prime is 2025021787. The reversal of 2025021781 is 1871205202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1586747556 + 438274225 = 39834^2 + 20935^2 .

It is a cyclic number.

It is not a de Polignac number, because 2025021781 - 2⁵ = 2025021749 is a prime.

It is a super-2 number, since 2×2025021781² = 8201426427048823922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2025021787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1012510890 + 1012510891.

It is an arithmetic number, because the mean of its divisors is an integer number (1012510891).

Almost surely, 2^2025021781 is an apocalyptic number.

It is an amenable number.

2025021781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2025021781 is an equidigital number, since it uses as much as digits as its factorization.

2025021781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 2025021781 is about 45000.2420104603. The cubic root of 2025021781 is about 1265.1535339381.

Adding to 2025021781 its reverse (1871205202), we get a palindrome (3896226983).

The spelling of 2025021781 in words is "two billion, twenty-five million, twenty-one thousand, seven hundred eighty-one".