55390402 has 4 divisors (see below), whose sum is σ = 83085606. Its totient is φ = 27695200.

The previous prime is 55390381. The next prime is 55390409. The reversal of 55390402 is 20409355.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20409355 = 5 ⋅4081871.

It can be written as a sum of positive squares in only one way, i.e., 49294441 + 6095961 = 7021^2 + 2469^2 .

It is not an unprimeable number, because it can be changed into a prime (55390409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13847599 + ... + 13847602.

Almost surely, 2^55390402 is an apocalyptic number.

55390402 is a deficient number, since it is larger than the sum of its proper divisors (27695204).

55390402 is a wasteful number, since it uses less digits than its factorization.

55390402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27695203.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 55390402 is about 7442.4728417375. The cubic root of 55390402 is about 381.1929316354.

Adding to 55390402 its reverse (20409355), we get a palindrome (75799757).

The spelling of 55390402 in words is "fifty-five million, three hundred ninety thousand, four hundred two".