1051781999 has 2 divisors, whose sum is σ = 1051782000. Its totient is φ = 1051781998.

The previous prime is 1051781989. The next prime is 1051782023. The reversal of 1051781999 is 9991871501.

It is a weak prime.

It is an emirp because it is prime and its reverse (9991871501) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1051781999 is a prime.

It is a super-2 number, since 2×1051781999² = 2212490746840872002, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1051781909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 525890999 + 525891000.

It is an arithmetic number, because the mean of its divisors is an integer number (525891000).

Almost surely, 2^1051781999 is an apocalyptic number.

1051781999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1051781999 is an equidigital number, since it uses as much as digits as its factorization.

1051781999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 204120, while the sum is 50.

The square root of 1051781999 is about 32431.1886769511. The cubic root of 1051781999 is about 1016.9710214579.

The spelling of 1051781999 in words is "one billion, fifty-one million, seven hundred eighty-one thousand, nine hundred ninety-nine".