77921212 has 6 divisors (see below), whose sum is σ = 136362128. Its totient is φ = 38960604.

The previous prime is 77921161. The next prime is 77921213. The reversal of 77921212 is 21212977.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77921213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9740148 + ... + 9740155.

Almost surely, 2^77921212 is an apocalyptic number.

It is an amenable number.

77921212 is a deficient number, since it is larger than the sum of its proper divisors (58440916).

77921212 is a wasteful number, since it uses less digits than its factorization.

77921212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19480307 (or 19480305 counting only the distinct ones).

The product of its digits is 3528, while the sum is 31.

The square root of 77921212 is about 8827.2992472217. The cubic root of 77921212 is about 427.1219589215.

The spelling of 77921212 in words is "seventy-seven million, nine hundred twenty-one thousand, two hundred twelve".