28051951 has 4 divisors (see below), whose sum is σ = 28076112. Its totient is φ = 28027792.

The previous prime is 28051943. The next prime is 28051981. The reversal of 28051951 is 15915082.

28051951 = T₄₃₂₃ + T₄₃₂₄ + T₄₃₂₅.

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

It is a cyclic number.

It is not a de Polignac number, because 28051951 - 2³ = 28051943 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28051981) 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, 10246 + ... + 12691.

It is an arithmetic number, because the mean of its divisors is an integer number (7019028).

Almost surely, 2^28051951 is an apocalyptic number.

28051951 is the 4325-th centered triangular number.

28051951 is a deficient number, since it is larger than the sum of its proper divisors (24161).

28051951 is a wasteful number, since it uses less digits than its factorization.

28051951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24160.

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 28051951 is about 5296.4092553352. The cubic root of 28051951 is about 303.8465833411.

The spelling of 28051951 in words is "twenty-eight million, fifty-one thousand, nine hundred fifty-one".