40172421 has 8 divisors (see below), whose sum is σ = 55892160. Its totient is φ = 25617152.

The previous prime is 40172413. The next prime is 40172423. The reversal of 40172421 is 12427104.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 40172421 - 2³ = 40172413 is a prime.

It is a super-2 number, since 2×40172421² = 3227646818002482, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40172423) 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, 291036 + ... + 291173.

It is an arithmetic number, because the mean of its divisors is an integer number (6986520).

Almost surely, 2^40172421 is an apocalyptic number.

It is an amenable number.

40172421 is a deficient number, since it is larger than the sum of its proper divisors (15719739).

40172421 is a wasteful number, since it uses less digits than its factorization.

40172421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 582235.

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 40172421 is about 6338.1717395476. The cubic root of 40172421 is about 342.4858779053.

Adding to 40172421 its reverse (12427104), we get a palindrome (52599525).

The spelling of 40172421 in words is "forty million, one hundred seventy-two thousand, four hundred twenty-one".