538721220 has 24 divisors (see below), whose sum is σ = 1508419584. Its totient is φ = 143658976.

The previous prime is 538721207. The next prime is 538721237. The reversal of 538721220 is 22127835.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4489284 + ... + 4489403.

It is an arithmetic number, because the mean of its divisors is an integer number (62850816).

Almost surely, 2^538721220 is an apocalyptic number.

It is an amenable number.

538721220 is an abundant number, since it is smaller than the sum of its proper divisors (969698364).

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

538721220 is a wasteful number, since it uses less digits than its factorization.

538721220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8978699 (or 8978697 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 538721220 is about 23210.3688036188. The cubic root of 538721220 is about 813.6819726474.

The spelling of 538721220 in words is "five hundred thirty-eight million, seven hundred twenty-one thousand, two hundred twenty".