76440205421 has 2 divisors, whose sum is σ = 76440205422. Its totient is φ = 76440205420.

The previous prime is 76440205399. The next prime is 76440205469. The reversal of 76440205421 is 12450204467.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58860097321 + 17580108100 = 242611^2 + 132590^2 .

It is an emirp because it is prime and its reverse (12450204467) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 76440205421 - 2³⁴ = 59260336237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (76440201421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38220102710 + 38220102711.

It is an arithmetic number, because the mean of its divisors is an integer number (38220102711).

Almost surely, 2^76440205421 is an apocalyptic number.

It is an amenable number.

76440205421 is a deficient number, since it is larger than the sum of its proper divisors (1).

76440205421 is an equidigital number, since it uses as much as digits as its factorization.

76440205421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 53760, while the sum is 35.

Adding to 76440205421 its reverse (12450204467), we get a palindrome (88890409888).

The spelling of 76440205421 in words is "seventy-six billion, four hundred forty million, two hundred five thousand, four hundred twenty-one".