51193990 has 16 divisors (see below), whose sum is σ = 95327280. Its totient is φ = 19771360.

The previous prime is 51193979. The next prime is 51193991. The reversal of 51193990 is 9939115.

It is a super-2 number, since 2×51193990² = 5241649224240200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51193991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87976 + ... + 88555.

It is an arithmetic number, because the mean of its divisors is an integer number (5957955).

Almost surely, 2^51193990 is an apocalyptic number.

51193990 is a deficient number, since it is larger than the sum of its proper divisors (44133290).

51193990 is a wasteful number, since it uses less digits than its factorization.

51193990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176567.

The product of its (nonzero) digits is 10935, while the sum is 37.

The square root of 51193990 is about 7154.9975541575. The cubic root of 51193990 is about 371.3125769804.

The spelling of 51193990 in words is "fifty-one million, one hundred ninety-three thousand, nine hundred ninety".