125221981 has 2 divisors, whose sum is σ = 125221982. Its totient is φ = 125221980.

The previous prime is 125221969. The next prime is 125221991. The reversal of 125221981 is 189122521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120231225 + 4990756 = 10965^2 + 2234^2 .

It is a cyclic number.

It is not a de Polignac number, because 125221981 - 2⁹ = 125221469 is a prime.

It is a super-2 number, since 2×125221981² = 31361089051128722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125221961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62610990 + 62610991.

It is an arithmetic number, because the mean of its divisors is an integer number (62610991).

Almost surely, 2^125221981 is an apocalyptic number.

It is an amenable number.

125221981 is a deficient number, since it is larger than the sum of its proper divisors (1).

125221981 is an equidigital number, since it uses as much as digits as its factorization.

125221981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 31.

The square root of 125221981 is about 11190.2627761818. The cubic root of 125221981 is about 500.2957996373.

The spelling of 125221981 in words is "one hundred twenty-five million, two hundred twenty-one thousand, nine hundred eighty-one".