10621991 has 8 divisors (see below), whose sum is σ = 11432304. Its totient is φ = 9832320.

The previous prime is 10621981. The next prime is 10621999. The reversal of 10621991 is 19912601.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 10621991 - 2⁶ = 10621927 is a prime.

It is a super-2 number, since 2×10621991² = 225653385608162, 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 (10621999) 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, 4085 + ... + 6158.

It is an arithmetic number, because the mean of its divisors is an integer number (1429038).

Almost surely, 2^10621991 is an apocalyptic number.

10621991 is a deficient number, since it is larger than the sum of its proper divisors (810313).

10621991 is a wasteful number, since it uses less digits than its factorization.

10621991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10321.

The product of its (nonzero) digits is 972, while the sum is 29.

The square root of 10621991 is about 3259.1396103880. The cubic root of 10621991 is about 219.8207286125.

The spelling of 10621991 in words is "ten million, six hundred twenty-one thousand, nine hundred ninety-one".