77528921 has 2 divisors, whose sum is σ = 77528922. Its totient is φ = 77528920.

The previous prime is 77528863. The next prime is 77528951. The reversal of 77528921 is 12982577.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44408896 + 33120025 = 6664^2 + 5755^2 .

It is a cyclic number.

It is not a de Polignac number, because 77528921 - 2¹⁰ = 77527897 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (77528951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38764460 + 38764461.

It is an arithmetic number, because the mean of its divisors is an integer number (38764461).

Almost surely, 2^77528921 is an apocalyptic number.

It is an amenable number.

77528921 is a deficient number, since it is larger than the sum of its proper divisors (1).

77528921 is an equidigital number, since it uses as much as digits as its factorization.

77528921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 70560, while the sum is 41.

The square root of 77528921 is about 8805.0508800347. The cubic root of 77528921 is about 426.4039769590.

The spelling of 77528921 in words is "seventy-seven million, five hundred twenty-eight thousand, nine hundred twenty-one".