77892121 has 2 divisors, whose sum is σ = 77892122. Its totient is φ = 77892120.

The previous prime is 77892107. The next prime is 77892137. The reversal of 77892121 is 12129877.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71318025 + 6574096 = 8445^2 + 2564^2 .

It is a cyclic number.

It is not a de Polignac number, because 77892121 - 2¹³ = 77883929 is a prime.

It is not a weakly prime, because it can be changed into another prime (77892721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38946060 + 38946061.

It is an arithmetic number, because the mean of its divisors is an integer number (38946061).

Almost surely, 2^77892121 is an apocalyptic number.

It is an amenable number.

77892121 is a deficient number, since it is larger than the sum of its proper divisors (1).

77892121 is an equidigital number, since it uses as much as digits as its factorization.

77892121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14112, while the sum is 37.

The square root of 77892121 is about 8825.6513074107. The cubic root of 77892121 is about 427.0687985937.

The spelling of 77892121 in words is "seventy-seven million, eight hundred ninety-two thousand, one hundred twenty-one".