77000021 has 24 divisors (see below), whose sum is σ = 98988480. Its totient is φ = 59402112.

The previous prime is 77000003. The next prime is 77000029. The reversal of 77000021 is 12000077.

It is a happy number.

It is not a de Polignac number, because 77000021 - 2¹⁰ = 76998997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77000029) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17150 + ... + 21168.

It is an arithmetic number, because the mean of its divisors is an integer number (4124520).

Almost surely, 2^77000021 is an apocalyptic number.

It is an amenable number.

77000021 is a deficient number, since it is larger than the sum of its proper divisors (21988459).

77000021 is a wasteful number, since it uses less digits than its factorization.

77000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4073 (or 4066 counting only the distinct ones).

The product of its (nonzero) digits is 98, while the sum is 17.

The square root of 77000021 is about 8774.9655839781. The cubic root of 77000021 is about 425.4321251871.

Adding to 77000021 its reverse (12000077), we get a palindrome (89000098).

The spelling of 77000021 in words is "seventy-seven million, twenty-one", and thus it is an aban number and an uban number.