861720813542 has 4 divisors (see below), whose sum is σ = 1292581220316. Its totient is φ = 430860406770.

The previous prime is 861720813539. The next prime is 861720813553. The reversal of 861720813542 is 245318027168.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 215430203384 + ... + 215430203387.

It is an arithmetic number, because the mean of its divisors is an integer number (323145305079).

Almost surely, 2^861720813542 is an apocalyptic number.

861720813542 is a deficient number, since it is larger than the sum of its proper divisors (430860406774).

861720813542 is a wasteful number, since it uses less digits than its factorization.

861720813542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430860406773.

The product of its (nonzero) digits is 645120, while the sum is 47.

The spelling of 861720813542 in words is "eight hundred sixty-one billion, seven hundred twenty million, eight hundred thirteen thousand, five hundred forty-two".