77400551 has 2 divisors, whose sum is σ = 77400552. Its totient is φ = 77400550.

The previous prime is 77400523. The next prime is 77400553. The reversal of 77400551 is 15500477.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77400551 is a prime.

Together with 77400553, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77400553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38700275 + 38700276.

It is an arithmetic number, because the mean of its divisors is an integer number (38700276).

Almost surely, 2^77400551 is an apocalyptic number.

77400551 is a deficient number, since it is larger than the sum of its proper divisors (1).

77400551 is an equidigital number, since it uses as much as digits as its factorization.

77400551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4900, while the sum is 29.

The square root of 77400551 is about 8797.7582940201. The cubic root of 77400551 is about 426.1685047570.

The spelling of 77400551 in words is "seventy-seven million, four hundred thousand, five hundred fifty-one".