221407157 has 2 divisors, whose sum is σ = 221407158. Its totient is φ = 221407156.

The previous prime is 221407127. The next prime is 221407159. The reversal of 221407157 is 751704122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 176597521 + 44809636 = 13289^2 + 6694^2 .

It is a cyclic number.

It is not a de Polignac number, because 221407157 - 2²⁰ = 220358581 is a prime.

It is a super-2 number, since 2×221407157² = 98042258341645298, which contains 22 as substring.

Together with 221407159, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221407159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110703578 + 110703579.

It is an arithmetic number, because the mean of its divisors is an integer number (110703579).

Almost surely, 2^221407157 is an apocalyptic number.

It is an amenable number.

221407157 is a deficient number, since it is larger than the sum of its proper divisors (1).

221407157 is an equidigital number, since it uses as much as digits as its factorization.

221407157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3920, while the sum is 29.

The square root of 221407157 is about 14879.7566176332. The cubic root of 221407157 is about 604.9654211505.

The spelling of 221407157 in words is "two hundred twenty-one million, four hundred seven thousand, one hundred fifty-seven".