1215640206 has 96 divisors (see below), whose sum is σ = 3017544192. Its totient is φ = 350095680.

The previous prime is 1215640187. The next prime is 1215640243. The reversal of 1215640206 is 6020465121.

1215640206 is a `hidden beast` number, since 1 + 2 + 15 + 640 + 2 + 0 + 6 = 666.

It is a super-2 number, since 2×1215640206² = 2955562220887444872, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1215640206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 787071 + ... + 788613.

It is an arithmetic number, because the mean of its divisors is an integer number (31432752).

Almost surely, 2^1215640206 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1215640206, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1508772096).

1215640206 is an abundant number, since it is smaller than the sum of its proper divisors (1801903986).

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

1215640206 is a wasteful number, since it uses less digits than its factorization.

1215640206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1758 (or 1755 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 1215640206 is about 34866.0322663764. The cubic root of 1215640206 is about 1067.2553777335.

The spelling of 1215640206 in words is "one billion, two hundred fifteen million, six hundred forty thousand, two hundred six".