77604021 has 32 divisors (see below), whose sum is σ = 128499840. Its totient is φ = 45878400.

The previous prime is 77604019. The next prime is 77604041. The reversal of 77604021 is 12040677.

It is not a de Polignac number, because 77604021 - 2¹ = 77604019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77604041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8991 + ... + 15363.

It is an arithmetic number, because the mean of its divisors is an integer number (4015620).

Almost surely, 2^77604021 is an apocalyptic number.

It is an amenable number.

77604021 is a deficient number, since it is larger than the sum of its proper divisors (50895819).

77604021 is a wasteful number, since it uses less digits than its factorization.

77604021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6434 (or 6428 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 77604021 is about 8809.3144455173. The cubic root of 77604021 is about 426.5416142171.

Adding to 77604021 its reverse (12040677), we get a palindrome (89644698).

It can be divided in two parts, 7760 and 4021, that added together give a triangular number (11781 = T₁₅₃).

The spelling of 77604021 in words is "seventy-seven million, six hundred four thousand, twenty-one".