42401521 has 16 divisors (see below), whose sum is σ = 46435840. Its totient is φ = 38568960.

The previous prime is 42401501. The next prime is 42401531. The reversal of 42401521 is 12510424.

42401521 = T₂₇₈ + T₂₇₉ + ... + T₆₅₀.

It is not a de Polignac number, because 42401521 - 2¹¹ = 42399473 is a prime.

It is a super-2 number, since 2×42401521² = 3595777966226882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42401501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113491 + ... + 113863.

It is an arithmetic number, because the mean of its divisors is an integer number (2902240).

Almost surely, 2^42401521 is an apocalyptic number.

42401521 is the 3760-th hex number.

It is an amenable number.

42401521 is a deficient number, since it is larger than the sum of its proper divisors (4034319).

42401521 is a wasteful number, since it uses less digits than its factorization.

42401521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 616.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 42401521 is about 6511.6450302516. The cubic root of 42401521 is about 348.7068498319.

Adding to 42401521 its reverse (12510424), we get a palindrome (54911945).

The spelling of 42401521 in words is "forty-two million, four hundred one thousand, five hundred twenty-one".