61642538971 has 4 divisors (see below), whose sum is σ = 66384272752. Its totient is φ = 56900805192.

The previous prime is 61642538959. The next prime is 61642538977. The reversal of 61642538971 is 17983524616.

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

It is a cyclic number.

It is not a de Polignac number, because 61642538971 - 2²³ = 61634150363 is a prime.

It is a super-2 number, since 2×61642538971² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61642538977) 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, 2370866871 + ... + 2370866896.

It is an arithmetic number, because the mean of its divisors is an integer number (16596068188).

Almost surely, 2^61642538971 is an apocalyptic number.

61642538971 is a deficient number, since it is larger than the sum of its proper divisors (4741733781).

61642538971 is a wasteful number, since it uses less digits than its factorization.

61642538971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4741733780.

The product of its digits is 2177280, while the sum is 52.

The spelling of 61642538971 in words is "sixty-one billion, six hundred forty-two million, five hundred thirty-eight thousand, nine hundred seventy-one".