77137921 has 4 divisors (see below), whose sum is σ = 88157632. Its totient is φ = 66118212.

The previous prime is 77137903. The next prime is 77137937. The reversal of 77137921 is 12973177.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 77137921 - 2¹¹ = 77135873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77137901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5509845 + ... + 5509858.

It is an arithmetic number, because the mean of its divisors is an integer number (22039408).

Almost surely, 2^77137921 is an apocalyptic number.

It is an amenable number.

77137921 is a deficient number, since it is larger than the sum of its proper divisors (11019711).

77137921 is a wasteful number, since it uses less digits than its factorization.

77137921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11019710.

The product of its digits is 18522, while the sum is 37.

The square root of 77137921 is about 8782.8196497480. The cubic root of 77137921 is about 425.6859437430.

The spelling of 77137921 in words is "seventy-seven million, one hundred thirty-seven thousand, nine hundred twenty-one".