1521225020 has 24 divisors (see below), whose sum is σ = 3650940384. Its totient is φ = 521562816.

The previous prime is 1521224917. The next prime is 1521225023. The reversal of 1521225020 is 205221251.

It is a happy number.

It is a super-2 number, since 2×1521225020² = 4628251122948000800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1521224983 and 1521225001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1521225023) 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, 5432807 + ... + 5433086.

It is an arithmetic number, because the mean of its divisors is an integer number (152122516).

Almost surely, 2^1521225020 is an apocalyptic number.

1521225020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1521225020 is an abundant number, since it is smaller than the sum of its proper divisors (2129715364).

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

1521225020 is a wasteful number, since it uses less digits than its factorization.

1521225020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10865909 (or 10865907 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 1521225020 is about 39002.8847651042. The cubic root of 1521225020 is about 1150.0882150351.

Adding to 1521225020 its reverse (205221251), we get a palindrome (1726446271).

The spelling of 1521225020 in words is "one billion, five hundred twenty-one million, two hundred twenty-five thousand, twenty".