81381853400 has 24 divisors (see below), whose sum is σ = 189212809620. Its totient is φ = 32552741280.

The previous prime is 81381853369. The next prime is 81381853411. The reversal of 81381853400 is 435818318.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 203454434 + ... + 203454833.

Almost surely, 2^81381853400 is an apocalyptic number.

It is an amenable number.

81381853400 is an abundant number, since it is smaller than the sum of its proper divisors (107830956220).

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

81381853400 is a wasteful number, since it uses less digits than its factorization.

81381853400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406909283 (or 406909274 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 41.

The spelling of 81381853400 in words is "eighty-one billion, three hundred eighty-one million, eight hundred fifty-three thousand, four hundred".