77630021 has 8 divisors (see below), whose sum is σ = 88773504. Its totient is φ = 66499920.

The previous prime is 77629999. The next prime is 77630023. The reversal of 77630021 is 12003677.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77630021 - 2¹⁸ = 77367877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77630023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19616 + ... + 23238.

It is an arithmetic number, because the mean of its divisors is an integer number (11096688).

Almost surely, 2^77630021 is an apocalyptic number.

It is an amenable number.

77630021 is a deficient number, since it is larger than the sum of its proper divisors (11143483).

77630021 is a wasteful number, since it uses less digits than its factorization.

77630021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6691.

The product of its (nonzero) digits is 1764, while the sum is 26.

The square root of 77630021 is about 8810.7900326815. The cubic root of 77630021 is about 426.5892442391.

Adding to 77630021 its reverse (12003677), we get a palindrome (89633698).

The spelling of 77630021 in words is "seventy-seven million, six hundred thirty thousand, twenty-one".