2171871731450 has 24 divisors (see below), whose sum is σ = 4041771451068. Its totient is φ = 868299223680.

The previous prime is 2171871731429. The next prime is 2171871731489. The reversal of 2171871731450 is 541371781712.

It can be written as a sum of positive squares in 6 ways, for example, as 674765316481 + 1497106414969 = 821441^2 + 1223563^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2171871731395 and 2171871731404.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11139107 + ... + 11332406.

Almost surely, 2^{2171871731450} is an apocalyptic number.

2171871731450 is a deficient number, since it is larger than the sum of its proper divisors (1869899719618).

2171871731450 is a wasteful number, since it uses less digits than its factorization.

2171871731450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22473458 (or 22473453 counting only the distinct ones).

The product of its (nonzero) digits is 329280, while the sum is 47.

The spelling of 2171871731450 in words is "two trillion, one hundred seventy-one billion, eight hundred seventy-one million, seven hundred thirty-one thousand, four hundred fifty".