1021205345 has 16 divisors (see below), whose sum is σ = 1240337280. Its totient is φ = 807076224.

The previous prime is 1021205321. The next prime is 1021205347. The reversal of 1021205345 is 5435021201.

It is a cyclic number.

It is not a de Polignac number, because 1021205345 - 2²² = 1017011041 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1021205345.

It is not an unprimeable number, because it can be changed into a prime (1021205347) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 233186 + ... + 237524.

It is an arithmetic number, because the mean of its divisors is an integer number (77521080).

Almost surely, 2^1021205345 is an apocalyptic number.

It is an amenable number.

1021205345 is a deficient number, since it is larger than the sum of its proper divisors (219131935).

1021205345 is a wasteful number, since it uses less digits than its factorization.

1021205345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4904.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 1021205345 is about 31956.3036817464. The cubic root of 1021205345 is about 1007.0190657788.

Adding to 1021205345 its reverse (5435021201), we get a palindrome (6456226546).

The spelling of 1021205345 in words is "one billion, twenty-one million, two hundred five thousand, three hundred forty-five".