20400628 has 6 divisors (see below), whose sum is σ = 35701106. Its totient is φ = 10200312.

The previous prime is 20400599. The next prime is 20400631. The reversal of 20400628 is 82600402.

It can be written as a sum of positive squares in only one way, i.e., 19027044 + 1373584 = 4362^2 + 1172^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20400599 and 20400608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2550075 + ... + 2550082.

Almost surely, 2^20400628 is an apocalyptic number.

It is an amenable number.

20400628 is a deficient number, since it is larger than the sum of its proper divisors (15300478).

20400628 is a wasteful number, since it uses less digits than its factorization.

20400628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5100161 (or 5100159 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 20400628 is about 4516.7054364880. The cubic root of 20400628 is about 273.2422454102.

The spelling of 20400628 in words is "twenty million, four hundred thousand, six hundred twenty-eight".