65131861821 has 32 divisors (see below), whose sum is σ = 94536288000. Its totient is φ = 39647176704.

The previous prime is 65131861789. The next prime is 65131861903. The reversal of 65131861821 is 12816813156.

It is not a de Polignac number, because 65131861821 - 2⁵ = 65131861789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65131861621) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10396336 + ... + 10402598.

It is an arithmetic number, because the mean of its divisors is an integer number (2954259000).

Almost surely, 2^65131861821 is an apocalyptic number.

It is an amenable number.

65131861821 is a deficient number, since it is larger than the sum of its proper divisors (29404426179).

65131861821 is a wasteful number, since it uses less digits than its factorization.

65131861821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9125.

The product of its digits is 69120, while the sum is 42.

The spelling of 65131861821 in words is "sixty-five billion, one hundred thirty-one million, eight hundred sixty-one thousand, eight hundred twenty-one".