77494421 has 2 divisors, whose sum is σ = 77494422. Its totient is φ = 77494420.

The previous prime is 77494363. The next prime is 77494477. The reversal of 77494421 is 12449477.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75881521 + 1612900 = 8711^2 + 1270^2 .

It is a cyclic number.

It is not a de Polignac number, because 77494421 - 2⁶ = 77494357 is a prime.

It is a super-2 number, since 2×77494421² = 12010770572250482, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77494121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38747210 + 38747211.

It is an arithmetic number, because the mean of its divisors is an integer number (38747211).

Almost surely, 2^77494421 is an apocalyptic number.

It is an amenable number.

77494421 is a deficient number, since it is larger than the sum of its proper divisors (1).

77494421 is an equidigital number, since it uses as much as digits as its factorization.

77494421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 38.

The square root of 77494421 is about 8803.0915592194. The cubic root of 77494421 is about 426.3407183296.

The spelling of 77494421 in words is "seventy-seven million, four hundred ninety-four thousand, four hundred twenty-one".