53801981 has 4 divisors (see below), whose sum is σ = 54946752. Its totient is φ = 52657212.

The previous prime is 53801971. The next prime is 53801983. The reversal of 53801981 is 18910835.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18910835 = 5 ⋅3782167.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-53801981 is a prime.

It is a super-2 number, since 2×53801981² = 5789306319048722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53801983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 572315 + ... + 572408.

It is an arithmetic number, because the mean of its divisors is an integer number (13736688).

Almost surely, 2^53801981 is an apocalyptic number.

It is an amenable number.

53801981 is a deficient number, since it is larger than the sum of its proper divisors (1144771).

53801981 is a wasteful number, since it uses less digits than its factorization.

53801981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1144770.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 53801981 is about 7334.9833673976. The cubic root of 53801981 is about 377.5137336933.

The spelling of 53801981 in words is "fifty-three million, eight hundred one thousand, nine hundred eighty-one".