20278730 has 8 divisors (see below), whose sum is σ = 36501732. Its totient is φ = 8111488.

The previous prime is 20278729. The next prime is 20278759. The reversal of 20278730 is 3787202.

It can be written as a sum of positive squares in 2 ways, for example, as 17631601 + 2647129 = 4199^2 + 1627^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×20278730² = 822453780825800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20278693 and 20278702.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1013927 + ... + 1013946.

Almost surely, 2^20278730 is an apocalyptic number.

20278730 is a deficient number, since it is larger than the sum of its proper divisors (16223002).

20278730 is a wasteful number, since it uses less digits than its factorization.

20278730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2027880.

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 20278730 is about 4503.1910907711. The cubic root of 20278730 is about 272.6969314058.

The spelling of 20278730 in words is "twenty million, two hundred seventy-eight thousand, seven hundred thirty".