981372551 has 4 divisors (see below), whose sum is σ = 981576504. Its totient is φ = 981168600.

The previous prime is 981372541. The next prime is 981372593. The reversal of 981372551 is 155273189.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155273189 = 17 ⋅9133717.

It is a cyclic number.

It is not a de Polignac number, because 981372551 - 2¹⁸ = 981110407 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 981372499 and 981372508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981372541) 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, 94580 + ... + 104441.

It is an arithmetic number, because the mean of its divisors is an integer number (245394126).

Almost surely, 2^981372551 is an apocalyptic number.

981372551 is a deficient number, since it is larger than the sum of its proper divisors (203953).

981372551 is a wasteful number, since it uses less digits than its factorization.

981372551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203952.

The product of its digits is 75600, while the sum is 41.

The square root of 981372551 is about 31326.8662811970. The cubic root of 981372551 is about 993.7518927960.

The spelling of 981372551 in words is "nine hundred eighty-one million, three hundred seventy-two thousand, five hundred fifty-one".