91378410642640 has 40 divisors (see below), whose sum is σ = 231768877904928. Its totient is φ = 33228512960640.

The previous prime is 91378410642601. The next prime is 91378410642643. The reversal of 91378410642640 is 4624601487319.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91378410642643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51919550622 + ... + 51919552381.

Almost surely, 2^{91378410642640} is an apocalyptic number.

It is an amenable number.

91378410642640 is an abundant number, since it is smaller than the sum of its proper divisors (140390467262288).

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

91378410642640 is a wasteful number, since it uses less digits than its factorization.

91378410642640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103839103027 (or 103839103021 counting only the distinct ones).

The product of its (nonzero) digits is 6967296, while the sum is 55.

The spelling of 91378410642640 in words is "ninety-one trillion, three hundred seventy-eight billion, four hundred ten million, six hundred forty-two thousand, six hundred forty".