1012020111 has 6 divisors (see below), whose sum is σ = 1461806840. Its totient is φ = 674680068.

The previous prime is 1012020091. The next prime is 1012020131. The reversal of 1012020111 is 1110202101.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1012020091) and next prime (1012020131).

It is a de Polignac number, because none of the positive numbers 2^k-1012020111 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 112446679 = 1012020111 / (1 + 0 + 1 + 2 + 0 + 2 + 0 + 1 + 1 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1012020093 and 1012020102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1012020131) 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, 56223331 + ... + 56223348.

Almost surely, 2^1012020111 is an apocalyptic number.

1012020111 is a deficient number, since it is larger than the sum of its proper divisors (449786729).

1012020111 is a wasteful number, since it uses less digits than its factorization.

1012020111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112446685 (or 112446682 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 1012020111 is about 31812.2635315376. The cubic root of 1012020111 is about 1003.9907563447.

Adding to 1012020111 its reverse (1110202101), we get a palindrome (2122222212).

The spelling of 1012020111 in words is "one billion, twelve million, twenty thousand, one hundred eleven".