91228561251 has 16 divisors (see below), whose sum is σ = 121775218560. Its totient is φ = 60750518400.

The previous prime is 91228561217. The next prime is 91228561309. The reversal of 91228561251 is 15216582219.

It is not a de Polignac number, because 91228561251 - 2⁶ = 91228561187 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91228561051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12240076 + ... + 12247526.

It is an arithmetic number, because the mean of its divisors is an integer number (7610951160).

Almost surely, 2^91228561251 is an apocalyptic number.

91228561251 is a deficient number, since it is larger than the sum of its proper divisors (30546657309).

91228561251 is a wasteful number, since it uses less digits than its factorization.

91228561251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11506.

The product of its digits is 86400, while the sum is 42.

The spelling of 91228561251 in words is "ninety-one billion, two hundred twenty-eight million, five hundred sixty-one thousand, two hundred fifty-one".