1971901386 has 96 divisors (see below), whose sum is σ = 5275740288. Its totient is φ = 518348160.

The previous prime is 1971901369. The next prime is 1971901387. The reversal of 1971901386 is 6831091791.

1971901386 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×1971901386² = 7776790152217441992, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1971901387) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 540360 + ... + 543996.

It is an arithmetic number, because the mean of its divisors is an integer number (54955628).

Almost surely, 2^1971901386 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1971901386, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2637870144).

1971901386 is an abundant number, since it is smaller than the sum of its proper divisors (3303838902).

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

1971901386 is a wasteful number, since it uses less digits than its factorization.

1971901386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3996 (or 3993 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 1971901386 is about 44406.0962706699. The cubic root of 1971901386 is about 1253.9928610813.

The spelling of 1971901386 in words is "one billion, nine hundred seventy-one million, nine hundred one thousand, three hundred eighty-six".