28723426 has 4 divisors (see below), whose sum is σ = 43085142. Its totient is φ = 14361712.

The previous prime is 28723423. The next prime is 28723447. The reversal of 28723426 is 62432782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 62432782 = 2 ⋅31216391.

It can be written as a sum of positive squares in only one way, i.e., 15217801 + 13505625 = 3901^2 + 3675^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28723391 and 28723400.

It is not an unprimeable number, because it can be changed into a prime (28723423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7180855 + ... + 7180858.

Almost surely, 2^28723426 is an apocalyptic number.

28723426 is a deficient number, since it is larger than the sum of its proper divisors (14361716).

28723426 is a wasteful number, since it uses less digits than its factorization.

28723426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14361715.

The product of its digits is 32256, while the sum is 34.

The square root of 28723426 is about 5359.4240362188. The cubic root of 28723426 is about 306.2518680436.

The spelling of 28723426 in words is "twenty-eight million, seven hundred twenty-three thousand, four hundred twenty-six".