72633981 has 16 divisors (see below), whose sum is σ = 112496768. Its totient is φ = 40824000.

The previous prime is 72633973. The next prime is 72633983. The reversal of 72633981 is 18933627.

It is not a de Polignac number, because 72633981 - 2³ = 72633973 is a prime.

It is a super-2 number, since 2×72633981² = 10551390391816722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72633983) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27070 + ... + 29631.

It is an arithmetic number, because the mean of its divisors is an integer number (7031048).

Almost surely, 2^72633981 is an apocalyptic number.

It is an amenable number.

72633981 is a deficient number, since it is larger than the sum of its proper divisors (39862787).

72633981 is a wasteful number, since it uses less digits than its factorization.

72633981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56772.

The product of its digits is 54432, while the sum is 39.

The square root of 72633981 is about 8522.5571866665. The cubic root of 72633981 is about 417.2342477907.

The spelling of 72633981 in words is "seventy-two million, six hundred thirty-three thousand, nine hundred eighty-one".