73970021 has 4 divisors (see below), whose sum is σ = 77863200. Its totient is φ = 70076844.

The previous prime is 73969979. The next prime is 73970041. The reversal of 73970021 is 12007937.

It is a happy number.

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: 12007937 = 2383 ⋅5039.

It is a cyclic number.

It is not a de Polignac number, because 73970021 - 2⁶ = 73969957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (73970041) 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, 1946561 + ... + 1946598.

It is an arithmetic number, because the mean of its divisors is an integer number (19465800).

Almost surely, 2^73970021 is an apocalyptic number.

It is an amenable number.

73970021 is a deficient number, since it is larger than the sum of its proper divisors (3893179).

73970021 is a wasteful number, since it uses less digits than its factorization.

73970021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3893178.

The product of its (nonzero) digits is 2646, while the sum is 29.

The square root of 73970021 is about 8600.5825965454. The cubic root of 73970021 is about 419.7769431606.

Adding to 73970021 its reverse (12007937), we get a palindrome (85977958).

The spelling of 73970021 in words is "seventy-three million, nine hundred seventy thousand, twenty-one".