1971043648 has 56 divisors (see below), whose sum is σ = 4733007552. Its totient is φ = 795039744.

The previous prime is 1971043639. The next prime is 1971043649. The reversal of 1971043648 is 8463401791.

It is a tau number, because it is divible by the number of its divisors (56).

It is a super-2 number, since 2×1971043648² = 7770026124642295808, which contains 22 as substring.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1971043649) 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, 121786 + ... + 137017.

It is an arithmetic number, because the mean of its divisors is an integer number (84517992).

Almost surely, 2^1971043648 is an apocalyptic number.

It is an amenable number.

1971043648 is an abundant number, since it is smaller than the sum of its proper divisors (2761963904).

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

1971043648 is a wasteful number, since it uses less digits than its factorization.

1971043648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258839 (or 258829 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 1971043648 is about 44396.4373345430. The cubic root of 1971043648 is about 1253.8110140362.

The spelling of 1971043648 in words is "one billion, nine hundred seventy-one million, forty-three thousand, six hundred forty-eight".