1011210021 has 8 divisors (see below), whose sum is σ = 1498088960. Its totient is φ = 674139996.
The previous prime is 1011209971. The next prime is 1011210023. The reversal of 1011210021 is 1200121101.
It is a happy number.
It is not a de Polignac number, because 1011210021 - 27 = 1011209893 is a prime.
It is a Harshad number since it is a multiple of its sum of digits (9).
It is a Duffinian number.
It is a junction number, because it is equal to n+sod(n) for n = 1011209985 and 1011210012.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1011210023) by changing a digit.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18726085 + ... + 18726138.
It is an arithmetic number, because the mean of its divisors is an integer number (187261120).
Almost surely, 21011210021 is an apocalyptic number.
It is an amenable number.
1011210021 is a deficient number, since it is larger than the sum of its proper divisors (486878939).
1011210021 is an equidigital number, since it uses as much as digits as its factorization.
1011210021 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 37452232 (or 37452226 counting only the distinct ones).
The product of its (nonzero) digits is 4, while the sum is 9.
The square root of 1011210021 is about 31799.5286285819. The cubic root of 1011210021 is about 1003.7227972490.
Adding to 1011210021 its reverse (1200121101), we get a palindrome (2211331122).
The spelling of 1011210021 in words is "one billion, eleven million, two hundred ten thousand, twenty-one".
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