50721021 has 12 divisors (see below), whose sum is σ = 78899548. Its totient is φ = 31212864.

The previous prime is 50721019. The next prime is 50721023. The reversal of 50721021 is 12012705.

It is an interprime number because it is at equal distance from previous prime (50721019) and next prime (50721023).

It can be written as a sum of positive squares in 2 ways, for example, as 9696996 + 41024025 = 3114^2 + 6405^2 .

It is not a de Polignac number, because 50721021 - 2¹ = 50721019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 50720985 and 50721003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (50721023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 216640 + ... + 216873.

Almost surely, 2^50721021 is an apocalyptic number.

It is an amenable number.

50721021 is a deficient number, since it is larger than the sum of its proper divisors (28178527).

50721021 is a wasteful number, since it uses less digits than its factorization.

50721021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433532 (or 433529 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 50721021 is about 7121.8692068866. The cubic root of 50721021 is about 370.1655480269.

Adding to 50721021 its reverse (12012705), we get a palindrome (62733726).

It can be divided in two parts, 507 and 21021, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 50721021 in words is "fifty million, seven hundred twenty-one thousand, twenty-one".