1921413749 has 4 divisors (see below), whose sum is σ = 1921649664. Its totient is φ = 1921177836.

The previous prime is 1921413743. The next prime is 1921413751. The reversal of 1921413749 is 9473141291.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1921413749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921413743) 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, 105287 + ... + 122180.

It is an arithmetic number, because the mean of its divisors is an integer number (480412416).

Almost surely, 2^1921413749 is an apocalyptic number.

It is an amenable number.

1921413749 is a deficient number, since it is larger than the sum of its proper divisors (235915).

1921413749 is an equidigital number, since it uses as much as digits as its factorization.

1921413749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235914.

The product of its digits is 54432, while the sum is 41.

The square root of 1921413749 is about 43833.9337614137. The cubic root of 1921413749 is about 1243.1979863466.

The spelling of 1921413749 in words is "one billion, nine hundred twenty-one million, four hundred thirteen thousand, seven hundred forty-nine".