655401121 has 2 divisors, whose sum is σ = 655401122. Its totient is φ = 655401120.

The previous prime is 655401107. The next prime is 655401133. The reversal of 655401121 is 121104556.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 612315025 + 43086096 = 24745^2 + 6564^2 .

It is a cyclic number.

It is not a de Polignac number, because 655401121 - 2¹³ = 655392929 is a prime.

It is not a weakly prime, because it can be changed into another prime (655401521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327700560 + 327700561.

It is an arithmetic number, because the mean of its divisors is an integer number (327700561).

Almost surely, 2^655401121 is an apocalyptic number.

It is an amenable number.

655401121 is a deficient number, since it is larger than the sum of its proper divisors (1).

655401121 is an equidigital number, since it uses as much as digits as its factorization.

655401121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 655401121 is about 25600.8031319332. The cubic root of 655401121 is about 868.6318041776.

Adding to 655401121 its reverse (121104556), we get a palindrome (776505677).

The spelling of 655401121 in words is "six hundred fifty-five million, four hundred one thousand, one hundred twenty-one".