19720450 has 12 divisors (see below), whose sum is σ = 36680130. Its totient is φ = 7888160.

The previous prime is 19720447. The next prime is 19720451. The reversal of 19720450 is 5402791.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 19280881 + 439569 = 4391^2 + 663^2 .

It is a super-2 number, since 2×19720450² = 777792296405000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19720451) 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, 197155 + ... + 197254.

Almost surely, 2^19720450 is an apocalyptic number.

19720450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19720450 is a deficient number, since it is larger than the sum of its proper divisors (16959680).

19720450 is a wasteful number, since it uses less digits than its factorization.

19720450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394421 (or 394416 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 19720450 is about 4440.7713293976. The cubic root of 19720450 is about 270.1711306519.

The spelling of 19720450 in words is "nineteen million, seven hundred twenty thousand, four hundred fifty".