157904221 has 2 divisors, whose sum is σ = 157904222. Its totient is φ = 157904220.

The previous prime is 157904209. The next prime is 157904233. The reversal of 157904221 is 122409751.

157904221 = 8885² + 8886².

It is a balanced prime because it is at equal distance from previous prime (157904209) and next prime (157904233).

It can be written as a sum of positive squares in only one way, i.e., 78960996 + 78943225 = 8886^2 + 8885^2 .

It is a cyclic number.

It is not a de Polignac number, because 157904221 - 2¹³ = 157896029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (157904251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78952110 + 78952111.

It is an arithmetic number, because the mean of its divisors is an integer number (78952111).

Almost surely, 2^157904221 is an apocalyptic number.

157904221 is the 8886-th centered square number.

It is an amenable number.

157904221 is a deficient number, since it is larger than the sum of its proper divisors (1).

157904221 is an equidigital number, since it uses as much as digits as its factorization.

157904221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 157904221 is about 12565.9946283611. The cubic root of 157904221 is about 540.5027565101.

The spelling of 157904221 in words is "one hundred fifty-seven million, nine hundred four thousand, two hundred twenty-one".