2139947640 has 128 divisors (see below), whose sum is σ = 7153920000. Its totient is φ = 568992384.

The previous prime is 2139947633. The next prime is 2139947687. The reversal of 2139947640 is 467499312.

It is a happy number.

2139947640 is a `hidden beast` number, since 2 + 139 + 9 + 476 + 40 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 393661 + ... + 399059.

It is an arithmetic number, because the mean of its divisors is an integer number (55890000).

Almost surely, 2^2139947640 is an apocalyptic number.

2139947640 is a gapful number since it is divisible by the number (20) 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 2139947640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3576960000).

2139947640 is an abundant number, since it is smaller than the sum of its proper divisors (5013972360).

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

2139947640 is a wasteful number, since it uses less digits than its factorization.

2139947640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5786 (or 5776 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The square root of 2139947640 is about 46259.5680913689. The cubic root of 2139947640 is about 1288.6482324608.

The spelling of 2139947640 in words is "two billion, one hundred thirty-nine million, nine hundred forty-seven thousand, six hundred forty".