77131421929 has 4 divisors (see below), whose sum is σ = 77157866884. Its totient is φ = 77104976976.

The previous prime is 77131421911. The next prime is 77131421989. The reversal of 77131421929 is 92912413177.

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

It can be written as a sum of positive squares in 2 ways, for example, as 67433702400 + 9697719529 = 259680^2 + 98477^2 .

It is a cyclic number.

It is not a de Polignac number, because 77131421929 - 2⁵ = 77131421897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77131421989) 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, 13218102 + ... + 13223935.

It is an arithmetic number, because the mean of its divisors is an integer number (19289466721).

Almost surely, 2^77131421929 is an apocalyptic number.

It is an amenable number.

77131421929 is a deficient number, since it is larger than the sum of its proper divisors (26444955).

77131421929 is a wasteful number, since it uses less digits than its factorization.

77131421929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26444954.

The product of its digits is 190512, while the sum is 46.

The spelling of 77131421929 in words is "seventy-seven billion, one hundred thirty-one million, four hundred twenty-one thousand, nine hundred twenty-nine".