73687921 has 2 divisors, whose sum is σ = 73687922. Its totient is φ = 73687920.

The previous prime is 73687903. The next prime is 73687937. The reversal of 73687921 is 12978637.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61402896 + 12285025 = 7836^2 + 3505^2 .

It is a cyclic number.

It is not a de Polignac number, because 73687921 - 2¹⁷ = 73556849 is a prime.

It is not a weakly prime, because it can be changed into another prime (73687021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36843960 + 36843961.

It is an arithmetic number, because the mean of its divisors is an integer number (36843961).

Almost surely, 2^73687921 is an apocalyptic number.

It is an amenable number.

73687921 is a deficient number, since it is larger than the sum of its proper divisors (1).

73687921 is an equidigital number, since it uses as much as digits as its factorization.

73687921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 43.

The square root of 73687921 is about 8584.1668786202. The cubic root of 73687921 is about 419.2426278962.

The spelling of 73687921 in words is "seventy-three million, six hundred eighty-seven thousand, nine hundred twenty-one".