91218401428 has 48 divisors (see below), whose sum is σ = 199062347904. Its totient is φ = 35532426240.

The previous prime is 91218401399. The next prime is 91218401447. The reversal of 91218401428 is 82410481219.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1641100 + ... + 1695772.

It is an arithmetic number, because the mean of its divisors is an integer number (4147132248).

Almost surely, 2^91218401428 is an apocalyptic number.

It is an amenable number.

91218401428 is an abundant number, since it is smaller than the sum of its proper divisors (107843946476).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91218401428 is a wasteful number, since it uses less digits than its factorization.

91218401428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60112 (or 60110 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 40.

The spelling of 91218401428 in words is "ninety-one billion, two hundred eighteen million, four hundred one thousand, four hundred twenty-eight".