73921047021 has 6 divisors (see below), whose sum is σ = 106774845710. Its totient is φ = 49280698008.

The previous prime is 73921047019. The next prime is 73921047029. The reversal of 73921047021 is 12074012937.

73921047021 is a `hidden beast` number, since 73 + 92 + 10 + 470 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 68513062500 + 5407984521 = 261750^2 + 73539^2 .

It is not a de Polignac number, because 73921047021 - 2¹ = 73921047019 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 (73921047029) 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, 4106724826 + ... + 4106724843.

Almost surely, 2^73921047021 is an apocalyptic number.

It is an amenable number.

73921047021 is a deficient number, since it is larger than the sum of its proper divisors (32853798689).

73921047021 is a wasteful number, since it uses less digits than its factorization.

73921047021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8213449675 (or 8213449672 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

Adding to 73921047021 its reverse (12074012937), we get a palindrome (85995059958).

The spelling of 73921047021 in words is "seventy-three billion, nine hundred twenty-one million, forty-seven thousand, twenty-one".