1021206165540 has 96 divisors (see below), whose sum is σ = 3119570979840. Its totient is φ = 247545264000.

The previous prime is 1021206165479. The next prime is 1021206165547. The reversal of 1021206165540 is 455616021201.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (1021206165547) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9218601 + ... + 9328719.

It is an arithmetic number, because the mean of its divisors is an integer number (32495531040).

Almost surely, 2^{1021206165540} is an apocalyptic number.

1021206165540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021206165540 is an abundant number, since it is smaller than the sum of its proper divisors (2098364814300).

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

1021206165540 is a wasteful number, since it uses less digits than its factorization.

1021206165540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124193 (or 124191 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 33.

The spelling of 1021206165540 in words is "one trillion, twenty-one billion, two hundred six million, one hundred sixty-five thousand, five hundred forty".