1221790572 has 18 divisors (see below), whose sum is σ = 3088415148. Its totient is φ = 407263512.

The previous prime is 1221790571. The next prime is 1221790589. The reversal of 1221790572 is 2750971221.

1221790572 is a `hidden beast` number, since 12 + 2 + 1 + 79 + 0 + 572 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 33938627 = 1221790572 / (1 + 2 + 2 + 1 + 7 + 9 + 0 + 5 + 7 + 2).

It is not an unprimeable number, because it can be changed into a prime (1221790571) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16969278 + ... + 16969349.

Almost surely, 2^1221790572 is an apocalyptic number.

1221790572 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221790572 is an abundant number, since it is smaller than the sum of its proper divisors (1866624576).

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

1221790572 is a wasteful number, since it uses less digits than its factorization.

1221790572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33938637 (or 33938632 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 36.

The square root of 1221790572 is about 34954.1209587654. The cubic root of 1221790572 is about 1069.0522285505.

The spelling of 1221790572 in words is "one billion, two hundred twenty-one million, seven hundred ninety thousand, five hundred seventy-two".