56172021 has 8 divisors (see below), whose sum is σ = 75668544. Its totient is φ = 37061760.

The previous prime is 56172019. The next prime is 56172023. The reversal of 56172021 is 12027165.

It is an interprime number because it is at equal distance from previous prime (56172019) and next prime (56172023).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 56172021 - 2¹ = 56172019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 56171982 and 56172000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56172023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96225 + ... + 96806.

It is an arithmetic number, because the mean of its divisors is an integer number (9458568).

Almost surely, 2^56172021 is an apocalyptic number.

It is an amenable number.

56172021 is a deficient number, since it is larger than the sum of its proper divisors (19496523).

56172021 is a wasteful number, since it uses less digits than its factorization.

56172021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193131.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 56172021 is about 7494.7995970539. The cubic root of 56172021 is about 382.9775793741.

Adding to 56172021 its reverse (12027165), we get a palindrome (68199186).

The spelling of 56172021 in words is "fifty-six million, one hundred seventy-two thousand, twenty-one".