61891543994 has 8 divisors (see below), whose sum is σ = 106099789728. Its totient is φ = 26524947420.

The previous prime is 61891543991. The next prime is 61891543997. The reversal of 61891543994 is 49934519816.

It is an interprime number because it is at equal distance from previous prime (61891543991) and next prime (61891543997).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×61891543994² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (61891543991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2210412272 + ... + 2210412299.

It is an arithmetic number, because the mean of its divisors is an integer number (13262473716).

Almost surely, 2^61891543994 is an apocalyptic number.

61891543994 is a deficient number, since it is larger than the sum of its proper divisors (44208245734).

61891543994 is a wasteful number, since it uses less digits than its factorization.

61891543994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4420824580.

The product of its digits is 8398080, while the sum is 59.

The spelling of 61891543994 in words is "sixty-one billion, eight hundred ninety-one million, five hundred forty-three thousand, nine hundred ninety-four".