1021020129 has 6 divisors (see below), whose sum is σ = 1474806866. Its totient is φ = 680680080.

The previous prime is 1021020109. The next prime is 1021020149. The reversal of 1021020129 is 9210201201.

It is an interprime number because it is at equal distance from previous prime (1021020109) and next prime (1021020149).

It can be written as a sum of positive squares in only one way, i.e., 990549729 + 30470400 = 31473^2 + 5520^2 .

It is not a de Polignac number, because 1021020129 - 2⁵ = 1021020097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1021020109) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 56723332 + ... + 56723349.

Almost surely, 2^1021020129 is an apocalyptic number.

It is an amenable number.

1021020129 is a deficient number, since it is larger than the sum of its proper divisors (453786737).

1021020129 is a wasteful number, since it uses less digits than its factorization.

1021020129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113446687 (or 113446684 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 1021020129 is about 31953.4055931445. The cubic root of 1021020129 is about 1006.9581810862.

The spelling of 1021020129 in words is "one billion, twenty-one million, twenty thousand, one hundred twenty-nine".