28151961 has 4 divisors (see below), whose sum is σ = 37535952. Its totient is φ = 18767972.

The previous prime is 28151951. The next prime is 28152001. The reversal of 28151961 is 16915182.

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 28151961 - 2⁷ = 28151833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28151941) 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, 4691991 + ... + 4691996.

It is an arithmetic number, because the mean of its divisors is an integer number (9383988).

Almost surely, 2^28151961 is an apocalyptic number.

It is an amenable number.

28151961 is a deficient number, since it is larger than the sum of its proper divisors (9383991).

28151961 is an equidigital number, since it uses as much as digits as its factorization.

28151961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9383990.

The product of its digits is 4320, while the sum is 33.

The square root of 28151961 is about 5305.8421574713. The cubic root of 28151961 is about 304.2072434097.

The spelling of 28151961 in words is "twenty-eight million, one hundred fifty-one thousand, nine hundred sixty-one".