15487421 has 4 divisors (see below), whose sum is σ = 16021500. Its totient is φ = 14953344.

The previous prime is 15487403. The next prime is 15487429. The reversal of 15487421 is 12478451.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6996025 + 8491396 = 2645^2 + 2914^2 .

It is a cyclic number.

It is not a de Polignac number, because 15487421 - 2¹⁸ = 15225277 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 (15487429) 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, 266996 + ... + 267053.

It is an arithmetic number, because the mean of its divisors is an integer number (4005375).

Almost surely, 2^15487421 is an apocalyptic number.

It is an amenable number.

15487421 is a deficient number, since it is larger than the sum of its proper divisors (534079).

15487421 is an equidigital number, since it uses as much as digits as its factorization.

15487421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 534078.

The product of its digits is 8960, while the sum is 32.

The square root of 15487421 is about 3935.4060781576. The cubic root of 15487421 is about 249.2640811528.

The spelling of 15487421 in words is "fifteen million, four hundred eighty-seven thousand, four hundred twenty-one".