1220420421 has 24 divisors (see below), whose sum is σ = 1944708480. Its totient is φ = 731332800.

The previous prime is 1220420419. The next prime is 1220420437. The reversal of 1220420421 is 1240240221.

1220420421 is a `hidden beast` number, since 1 + 220 + 4 + 20 + 421 = 666.

It is not a de Polignac number, because 1220420421 - 2¹ = 1220420419 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1220420394 and 1220420403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220420441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60445 + ... + 78066.

It is an arithmetic number, because the mean of its divisors is an integer number (81029520).

Almost surely, 2^1220420421 is an apocalyptic number.

1220420421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1220420421 is a deficient number, since it is larger than the sum of its proper divisors (724288059).

1220420421 is a wasteful number, since it uses less digits than its factorization.

1220420421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138617 (or 138614 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 1220420421 is about 34934.5161838546. The cubic root of 1220420421 is about 1068.6524571283.

Adding to 1220420421 its reverse (1240240221), we get a palindrome (2460660642).

The spelling of 1220420421 in words is "one billion, two hundred twenty million, four hundred twenty thousand, four hundred twenty-one".