77622021 has 6 divisors (see below), whose sum is σ = 112120710. Its totient is φ = 51748008.

The previous prime is 77622007. The next prime is 77622037. The reversal of 77622021 is 12022677.

It can be written as a sum of positive squares in only one way, i.e., 60233121 + 17388900 = 7761^2 + 4170^2 .

It is not a de Polignac number, because 77622021 - 2⁵ = 77621989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77622121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4312326 + ... + 4312343.

It is an arithmetic number, because the mean of its divisors is an integer number (18686785).

Almost surely, 2^77622021 is an apocalyptic number.

It is an amenable number.

77622021 is a deficient number, since it is larger than the sum of its proper divisors (34498689).

77622021 is a wasteful number, since it uses less digits than its factorization.

77622021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8624675 (or 8624672 counting only the distinct ones).

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

The square root of 77622021 is about 8810.3360321840. The cubic root of 77622021 is about 426.5745899806.

Adding to 77622021 its reverse (12022677), we get a palindrome (89644698).

The spelling of 77622021 in words is "seventy-seven million, six hundred twenty-two thousand, twenty-one".