15457421 has 4 divisors (see below), whose sum is σ = 17665632. Its totient is φ = 13249212.

The previous prime is 15457411. The next prime is 15457423. The reversal of 15457421 is 12475451.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12475451 = 107 ⋅116593.

It is a cyclic number.

It is not a de Polignac number, because 15457421 - 2¹⁴ = 15441037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15457423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1104095 + ... + 1104108.

It is an arithmetic number, because the mean of its divisors is an integer number (4416408).

Almost surely, 2^15457421 is an apocalyptic number.

It is an amenable number.

15457421 is a deficient number, since it is larger than the sum of its proper divisors (2208211).

15457421 is an equidigital number, since it uses as much as digits as its factorization.

15457421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2208210.

The product of its digits is 5600, while the sum is 29.

The square root of 15457421 is about 3931.5926798182. The cubic root of 15457421 is about 249.1030309684.

It can be divided in two parts, 154 and 57421, that added together give a palindrome (57575).

The spelling of 15457421 in words is "fifteen million, four hundred fifty-seven thousand, four hundred twenty-one".