1369991021 has 8 divisors (see below), whose sum is σ = 1633778304. Its totient is φ = 1123222320.

The previous prime is 1369991017. The next prime is 1369991069. The reversal of 1369991021 is 1201999631.

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 1369991021 - 2² = 1369991017 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1369991021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1369991921) 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, 4254470 + ... + 4254791.

It is an arithmetic number, because the mean of its divisors is an integer number (204222288).

Almost surely, 2^1369991021 is an apocalyptic number.

It is an amenable number.

1369991021 is a deficient number, since it is larger than the sum of its proper divisors (263787283).

1369991021 is an equidigital number, since it uses as much as digits as its factorization.

1369991021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8509291.

The product of its (nonzero) digits is 26244, while the sum is 41.

The square root of 1369991021 is about 37013.3897528989. The cubic root of 1369991021 is about 1110.6381150866.

The spelling of 1369991021 in words is "one billion, three hundred sixty-nine million, nine hundred ninety-one thousand, twenty-one".