861209507 has 2 divisors, whose sum is σ = 861209508. Its totient is φ = 861209506.

The previous prime is 861209467. The next prime is 861209533. The reversal of 861209507 is 705902168.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861209507 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (861209207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430604753 + 430604754.

It is an arithmetic number, because the mean of its divisors is an integer number (430604754).

Almost surely, 2^861209507 is an apocalyptic number.

861209507 is a deficient number, since it is larger than the sum of its proper divisors (1).

861209507 is an equidigital number, since it uses as much as digits as its factorization.

861209507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 861209507 is about 29346.3712748271. The cubic root of 861209507 is about 951.4141476282.

The spelling of 861209507 in words is "eight hundred sixty-one million, two hundred nine thousand, five hundred seven".