1021401220 has 24 divisors (see below), whose sum is σ = 2451363264. Its totient is φ = 350194656.

The previous prime is 1021401211. The next prime is 1021401287. The reversal of 1021401220 is 221041201.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1021401220.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3647722 + ... + 3648001.

It is an arithmetic number, because the mean of its divisors is an integer number (102140136).

Almost surely, 2^1021401220 is an apocalyptic number.

1021401220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021401220 is an abundant number, since it is smaller than the sum of its proper divisors (1429962044).

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

1021401220 is a wasteful number, since it uses less digits than its factorization.

1021401220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7295739 (or 7295737 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1021401220 is about 31959.3682665975. The cubic root of 1021401220 is about 1007.0834463171.

Adding to 1021401220 its reverse (221041201), we get a palindrome (1242442421).

The spelling of 1021401220 in words is "one billion, twenty-one million, four hundred one thousand, two hundred twenty".