1681901478 has 12 divisors (see below), whose sum is σ = 3644119908. Its totient is φ = 560633820.

The previous prime is 1681901471. The next prime is 1681901509. The reversal of 1681901478 is 8741091861.

It is a happy number.

1681901478 is a `hidden beast` number, since 16 + 81 + 90 + 1 + 478 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681901471) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 46719468 + ... + 46719503.

It is an arithmetic number, because the mean of its divisors is an integer number (303676659).

Almost surely, 2^1681901478 is an apocalyptic number.

1681901478 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1681901478 is an abundant number, since it is smaller than the sum of its proper divisors (1962218430).

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

1681901478 is a wasteful number, since it uses less digits than its factorization.

1681901478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93438979 (or 93438976 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 45.

The square root of 1681901478 is about 41010.9921606391. The cubic root of 1681901478 is about 1189.2327229109.

The spelling of 1681901478 in words is "one billion, six hundred eighty-one million, nine hundred one thousand, four hundred seventy-eight".