1821007157 has 2 divisors, whose sum is σ = 1821007158. Its totient is φ = 1821007156.

The previous prime is 1821007109. The next prime is 1821007159. The reversal of 1821007157 is 7517001281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1735055716 + 85951441 = 41654^2 + 9271^2 .

It is an emirp because it is prime and its reverse (7517001281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1821007157 - 2²² = 1816812853 is a prime.

Together with 1821007159, 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 (1821007159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910503578 + 910503579.

It is an arithmetic number, because the mean of its divisors is an integer number (910503579).

Almost surely, 2^1821007157 is an apocalyptic number.

It is an amenable number.

1821007157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821007157 is an equidigital number, since it uses as much as digits as its factorization.

1821007157 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 32.

The square root of 1821007157 is about 42673.2604449203. The cubic root of 1821007157 is about 1221.1543220149.

The spelling of 1821007157 in words is "one billion, eight hundred twenty-one million, seven thousand, one hundred fifty-seven".