245156921 has 2 divisors, whose sum is σ = 245156922. Its totient is φ = 245156920.

The previous prime is 245156893. The next prime is 245156963. The reversal of 245156921 is 129651542.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220106896 + 25050025 = 14836^2 + 5005^2 .

It is a cyclic number.

It is not a de Polignac number, because 245156921 - 2¹⁴ = 245140537 is a prime.

It is not a weakly prime, because it can be changed into another prime (245156321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122578460 + 122578461.

It is an arithmetic number, because the mean of its divisors is an integer number (122578461).

Almost surely, 2^245156921 is an apocalyptic number.

It is an amenable number.

245156921 is a deficient number, since it is larger than the sum of its proper divisors (1).

245156921 is an equidigital number, since it uses as much as digits as its factorization.

245156921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21600, while the sum is 35.

The square root of 245156921 is about 15657.4876975842. The cubic root of 245156921 is about 625.8660386623.

The spelling of 245156921 in words is "two hundred forty-five million, one hundred fifty-six thousand, nine hundred twenty-one".