1965743640 has 384 divisors, whose sum is σ = 7661122560. Its totient is φ = 444040704.

The previous prime is 1965743639. The next prime is 1965743641. The reversal of 1965743640 is 463475691.

1965743640 is a `hidden beast` number, since 1 + 9 + 6 + 574 + 36 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (1965743639) and next prime (1965743641).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1965743641) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11362594 + ... + 11362766.

It is an arithmetic number, because the mean of its divisors is an integer number (19950840).

Almost surely, 2^1965743640 is an apocalyptic number.

1965743640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1965743640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3830561280).

1965743640 is an abundant number, since it is smaller than the sum of its proper divisors (5695378920).

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

1965743640 is a wasteful number, since it uses less digits than its factorization.

1965743640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 1965743640 is about 44336.7075908891. The cubic root of 1965743640 is about 1252.6861998626.

The spelling of 1965743640 in words is "one billion, nine hundred sixty-five million, seven hundred forty-three thousand, six hundred forty".