815025551 has 2 divisors, whose sum is σ = 815025552. Its totient is φ = 815025550.

The previous prime is 815025503. The next prime is 815025553. The reversal of 815025551 is 155520518.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-815025551 is a prime.

Together with 815025553, 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 (815025553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 407512775 + 407512776.

It is an arithmetic number, because the mean of its divisors is an integer number (407512776).

Almost surely, 2^815025551 is an apocalyptic number.

815025551 is a deficient number, since it is larger than the sum of its proper divisors (1).

815025551 is an equidigital number, since it uses as much as digits as its factorization.

815025551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10000, while the sum is 32.

The square root of 815025551 is about 28548.6523499797. The cubic root of 815025551 is about 934.0936247885.

The spelling of 815025551 in words is "eight hundred fifteen million, twenty-five thousand, five hundred fifty-one".