40128621 has 8 divisors (see below), whose sum is σ = 57620640. Its totient is φ = 24694512.

The previous prime is 40128617. The next prime is 40128623. The reversal of 40128621 is 12682104.

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

It is not a de Polignac number, because 40128621 - 2² = 40128617 is a prime.

It is a super-2 number, since 2×40128621² = 3220612446723282, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 40128591 and 40128600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40128623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 514431 + ... + 514508.

It is an arithmetic number, because the mean of its divisors is an integer number (7202580).

Almost surely, 2^40128621 is an apocalyptic number.

It is an amenable number.

40128621 is a deficient number, since it is larger than the sum of its proper divisors (17492019).

40128621 is a wasteful number, since it uses less digits than its factorization.

40128621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1028955.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 40128621 is about 6334.7155421534. The cubic root of 40128621 is about 342.3613618301.

The spelling of 40128621 in words is "forty million, one hundred twenty-eight thousand, six hundred twenty-one".