73649921 has 4 divisors (see below), whose sum is σ = 73681344. Its totient is φ = 73618500.

The previous prime is 73649881. The next prime is 73649957. The reversal of 73649921 is 12994637.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12994637 = 617 ⋅21061.

It is a cyclic number.

It is not a de Polignac number, because 73649921 - 2²⁶ = 6541057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (73649221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11885 + ... + 16986.

It is an arithmetic number, because the mean of its divisors is an integer number (18420336).

Almost surely, 2^73649921 is an apocalyptic number.

It is an amenable number.

73649921 is a deficient number, since it is larger than the sum of its proper divisors (31423).

73649921 is a wasteful number, since it uses less digits than its factorization.

73649921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31422.

The product of its digits is 81648, while the sum is 41.

The square root of 73649921 is about 8581.9532159060. The cubic root of 73649921 is about 419.1705493296.

The spelling of 73649921 in words is "seventy-three million, six hundred forty-nine thousand, nine hundred twenty-one".