83778421 has 2 divisors, whose sum is σ = 83778422. Its totient is φ = 83778420.

The previous prime is 83778371. The next prime is 83778427. The reversal of 83778421 is 12487738.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79834225 + 3944196 = 8935^2 + 1986^2 .

It is a cyclic number.

It is not a de Polignac number, because 83778421 - 2⁹ = 83777909 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (83778427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41889210 + 41889211.

It is an arithmetic number, because the mean of its divisors is an integer number (41889211).

Almost surely, 2^83778421 is an apocalyptic number.

It is an amenable number.

83778421 is a deficient number, since it is larger than the sum of its proper divisors (1).

83778421 is an equidigital number, since it uses as much as digits as its factorization.

83778421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75264, while the sum is 40.

The square root of 83778421 is about 9153.0552822541. The cubic root of 83778421 is about 437.5664917715.

The spelling of 83778421 in words is "eighty-three million, seven hundred seventy-eight thousand, four hundred twenty-one".