1405792921 has 4 divisors (see below), whose sum is σ = 1513930852. Its totient is φ = 1297654992.

The previous prime is 1405792909. The next prime is 1405792943. The reversal of 1405792921 is 1292975041.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 61544025 + 1344248896 = 7845^2 + 36664^2 .

It is a cyclic number.

It is not a de Polignac number, because 1405792921 - 2²³ = 1397404313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1405792961) 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, 54068946 + ... + 54068971.

It is an arithmetic number, because the mean of its divisors is an integer number (378482713).

Almost surely, 2^1405792921 is an apocalyptic number.

It is an amenable number.

1405792921 is a deficient number, since it is larger than the sum of its proper divisors (108137931).

1405792921 is a wasteful number, since it uses less digits than its factorization.

1405792921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108137930.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 1405792921 is about 37493.9051180322. The cubic root of 1405792921 is about 1120.2297894263.

The spelling of 1405792921 in words is "one billion, four hundred five million, seven hundred ninety-two thousand, nine hundred twenty-one".