28213961 has 4 divisors (see below), whose sum is σ = 28227024. Its totient is φ = 28200900.

The previous prime is 28213957. The next prime is 28213963. The reversal of 28213961 is 16931282.

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.

It is a cyclic number.

It is not a de Polignac number, because 28213961 - 2² = 28213957 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28213963) 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, 2435 + ... + 7896.

It is an arithmetic number, because the mean of its divisors is an integer number (7056756).

Almost surely, 2^28213961 is an apocalyptic number.

It is an amenable number.

28213961 is a deficient number, since it is larger than the sum of its proper divisors (13063).

28213961 is a wasteful number, since it uses less digits than its factorization.

28213961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13062.

The product of its digits is 5184, while the sum is 32.

The square root of 28213961 is about 5311.6815604853. The cubic root of 28213961 is about 304.4304015768.

The spelling of 28213961 in words is "twenty-eight million, two hundred thirteen thousand, nine hundred sixty-one".